Abstract:

Vaccination has played an important role in the containment of COVID-19 pandemic advances. However, SARS-CoV-2 vaccine hesitancy has caused a global concern. This scoping review aims to map the scientific literature on COVID-19 vaccine hesitancy in Latin America and Africa from a Global Health perspective, observing the particularities of the Global South and using parameters validated by the World Health Organization (WHO). The review reporting observes the recommendations of the PRISMA for Scoping Reviews (PRISMA-ScR) model. Search was conducted in PubMed, Scopus, Web of Science, and Virtual Health Library (VHL) databases, selecting studies published from January 1, 2020 to January 22, 2022. Selected studies indicate that COVID-19 vaccine hesitancy involves factors such as political scenario, spread of misinformation, regional differences in each territory regarding Internet access, lack of access to information, history of vaccination resistance, lack of information about the disease and the vaccine, concern about adverse events, and vaccine efficacy and safety. Regarding the use of conceptual and methodology references from the WHO for vaccine hesitancy, few studies (6/94) use research instruments based on these references. Then, the replication in Global South of conceptual and methodological parameters developed by experts from the Global North contexts has been criticized from the perspective of Global Health because of it may not consider political and sociocultural particularities, the different nuances of vaccine hesitancy, and issues of access to vaccines.

Keywords:
Vaccination Hesitancy; COVID-19 Vaccines; Global Health

Introduction

The COVID-19 pandemic has exacerbated a complex Global Health scenario with the interaction of the SARS-CoV-2 and noncommunicable diseases, problems of health service access and functioning, socioeconomic inequality, and non-enforcement of social rights, making it a phenomenon of syndemic ¹1. Horton R. Offline: COVID-19 is not a pandemic. Lancet 2020; 396:874..

In addition to health measures such as physical distancing and hygiene, vaccination against COVID-19 significantly contributed to prevent the spread of the epidemic ²2. Lurie N, Saville M, Hatchett R, Halton J. Developing Covid-19 vaccines at pandemic speed. N Engl J Med 2020; 382:1969-73.. A successful vaccine campaign is directly related to the broad acceptance by the population and its effectiveness depends on sustained adoption to maintain the effect of immunity and stop the circulation of the infectious agent ³3. Streefland P, Chowdhury AM, Ramos-Jimenez P. Patterns of vaccination acceptance. Soc Sci Med 1999; 49:1705-16.. Despite knowledge legitimized by science about the effectiveness and success of mass immunization, social reactions against vaccines are seen in the history of immunization, creating challenges to Public Health ⁴4. Plotkin SA, Orenstein WA, Offit PA, Edwards KM, editors. Plotkin's vaccines. 7th Ed. Philadelphia: Elsevier; 2017..

Considering the importance of understanding and implementing actions to address this phenomenon, the working group on vaccine hesitancy of the Strategic Advisory Group of Experts on Immunization (SAGE), World Health Organization (WHO), defined vaccine hesitancy as the “delay in acceptance or refusal of vaccines despite availability of vaccination services” ⁵5. World Health Organization. Report of the SAGE Working Group on Vaccine Hesitancy. Geneva: World Health Organization; 2014. (p. 7). This definition excludes access issues ⁵5. World Health Organization. Report of the SAGE Working Group on Vaccine Hesitancy. Geneva: World Health Organization; 2014.^,66. World Health Organization. Appendices to Report of the SAGE working group on vaccine hesitancy. Geneva: World Health Organization; 2014., because “in low uptake situations where lack of available services is the major factor, hesitancy can be present but is not the principle reason for unvaccinated and undervaccinated members of the community” ⁵5. World Health Organization. Report of the SAGE Working Group on Vaccine Hesitancy. Geneva: World Health Organization; 2014. (p.7).

The WHO EURO Vaccine Communications Working Group proposed the 3C model (confidence, complacency, and convenience), based on the European experience with vaccine hesitancy, which was later reformulated into the 5C scale to include “risk calculation” and “collective responsibility” besides the three determinants of vaccine hesitancy present in the 3C model ⁷. The Matrix of Vaccine Hesitancy Determinants was created to guide the development of vaccine hesitancy indicators, research questions, diagnosis, and intervention ⁵5. World Health Organization. Report of the SAGE Working Group on Vaccine Hesitancy. Geneva: World Health Organization; 2014.^,66. World Health Organization. Appendices to Report of the SAGE working group on vaccine hesitancy. Geneva: World Health Organization; 2014.^,88. MacDonald NE. Vaccine hesitancy: definition, scope and determinants. Vaccine 2015; 33:4161-4.. The determinants are grouped into contextual, individual, and group influences/vaccine-specific issues ⁵5. World Health Organization. Report of the SAGE Working Group on Vaccine Hesitancy. Geneva: World Health Organization; 2014.^,66. World Health Organization. Appendices to Report of the SAGE working group on vaccine hesitancy. Geneva: World Health Organization; 2014.^,88. MacDonald NE. Vaccine hesitancy: definition, scope and determinants. Vaccine 2015; 33:4161-4.. It is not known whether this matrix was developed from the experiences and aspects of the Global North and South ⁹9. Matos CCSA, Gonçalves BA, Couto MT. Vaccine hesitancy in the global south: towards a critical perspective on global health. Glob Public Health 2022; 17:1087-98., but it has been recommended for studies at a global level and studies conducted in the Global South.

More recently, the Working Group on Behavioral and Social Drivers of Vaccination (BeSD), also linked with WHO, has developed another tool to understand the drivers and obstacles to vaccine uptake. The extensive document titled Behavioural and Social Drivers of Vaccination: Tools and Practical Guidance for Achieving High Uptake¹⁰10. World Health Organization. Behavioural and social drivers of vaccination: tools and practical guidance for achieving high uptake. Geneva: World Health Organization; 2022. contains surveys to investigate determinants of vaccine hesitancy, both in children and specifically regarding COVID-19 vaccines.

In the case of vaccination against COVID-19, studies conducted in African and Latin American countries showed that hesitancy was linked with religious beliefs, association between vaccination and surveillance of government authorities, lack of information about adverse events, vaccine safety and efficacy, and dissemination of fake news ¹¹11. Acheampong T, Akorsikumah EA, Osae-Kwapong J, Khalid M, Appiah A, Amuasi JH. Examining vaccine hesitancy in Sub-Saharan Africa: a survey of the knowledge and attitudes among adults to receive COVID-19 vaccines in Ghana. Vaccines (Basel) 2021; 9:814.^,1212. Dzinamarira T, Nachipo B, Phiri B, Musuka G. COVID-19 vaccine roll-out in South Africa and Zimbabwe: urgent need to address community preparedness, fears and hesitancy. Vaccines (Basel) 2021; 9:250.^,1313. Lima-Costa MF, Macinko J, Mambrini JVM. Hesitação vacinal contra a COVID-19 em amostra nacional de idosos brasileiros: iniciativa ELSI-COVID, março de 2021. Epidemiol Serv Saúde 2022; 31:e2021469.^,1414. Jaramillo-Monge J, Obimpeh M, Vega B, Acurio D, Boven A, Verhoeven V, et al. COVID-19 vaccine acceptance in Azuay Province, Ecuador: a cross-sectional online survey. Vaccines (Basel) 2021; 9:678.^,1515. Rodriguez M, López-Cepero A, Ortiz-Martínez AP, Fernández-Repollet E, Pérez CM. Influence of health beliefs on COVID-19 vaccination among individuals with cancer and other comorbidities in Puerto Rico. Vaccines (Basel) 2021; 9:994..

Previous scoping reviews sought to map COVID-19 vaccine hesitancy worldwide ¹⁶16. Biswas MR, Alzubaidi MS, Shah U, Abd-Alrazaq AA, Shah Z. A scoping review to find out worldwide COVID-19 vaccine hesitancy and its underlying determinants. Vaccines (Basel) 2021; 9:1243. and in high-income countries ¹⁷17. Aw J, Seng JJ, Seah SS, Low LL. COVID-19 vaccine hesitancy: a scoping review of literature in high-income countries. Vaccines (Basel) 2021; 9:900.. The results showed aspects related to hesitancy ¹⁶16. Biswas MR, Alzubaidi MS, Shah U, Abd-Alrazaq AA, Shah Z. A scoping review to find out worldwide COVID-19 vaccine hesitancy and its underlying determinants. Vaccines (Basel) 2021; 9:1243.^,1717. Aw J, Seng JJ, Seah SS, Low LL. COVID-19 vaccine hesitancy: a scoping review of literature in high-income countries. Vaccines (Basel) 2021; 9:900.: concerns about vaccine safety and efficacy, adverse events, perception of low risk in relation to COVID-19 infection, religious beliefs, cost of vaccine, rapid development of vaccines, lack of trust in government and health authorities, dissemination of fake information, unavailability of clear information about vaccines, racism and discrimination, preference for alternative treatments to the biomedical paradigm.

However, the method strategy of both studies only included publications in English ¹⁶16. Biswas MR, Alzubaidi MS, Shah U, Abd-Alrazaq AA, Shah Z. A scoping review to find out worldwide COVID-19 vaccine hesitancy and its underlying determinants. Vaccines (Basel) 2021; 9:1243.^,1717. Aw J, Seng JJ, Seah SS, Low LL. COVID-19 vaccine hesitancy: a scoping review of literature in high-income countries. Vaccines (Basel) 2021; 9:900.. Also, both reviews did not analyze the use of conceptual and methodological tools produced in the Global North applied to Global South countries. Then, our review conducted a reflective analysis on the realities of local contexts of the Global South, with a focus on how the frameworks proposed by WHO SAGE have been used in the Global Health in order to understand the phenomenon of COVID-19 vaccine hesitancy and the impact on health policies ¹⁸18. Montenegro CR, Bernales M, Gonzalez-Aguero M. Teaching global health from the south: challenges and proposals. Crit Public Health 2020; 30:127-9.^,1919. Guzman-Holst A, DeAntonio R, Prado-Cohrs D, Juliao P. Barriers to vaccination in Latin America: a systematic literature review. Vaccine 2020; 38:470-81.^,2020. Madhi SA, Rees H. Special focus on challenges and opportunities for the development and use of vaccines in Africa. Hum Vaccin Immunother 2018; 14:2335-9..

In this sense, this scoping review intends to promote original contributions to the particularities of social, cultural, and local aspects of COVID-19 vaccine hesitancy in Latin American and African countries from a critical perspective of Global Health ²¹21. Biehl J, Petryna A. When people come first: critical studies in global health. Princeton: Princeton University Press; 2013., which consider the relations of power, authority, inclusion and exclusion observed in the scientific field, governments, and health institutions in the Global North and Global South. This perspective highlights inequalities among actors who design and actors who receive global health interventions, in order to understand the reproduction of the dichotomy between “the West and the rest” ¹⁸18. Montenegro CR, Bernales M, Gonzalez-Aguero M. Teaching global health from the south: challenges and proposals. Crit Public Health 2020; 30:127-9..

Vaccine hesitancy in the Global South must be understood according to the complexity of cultural, social, ethnic, and regional differences ⁹9. Matos CCSA, Gonçalves BA, Couto MT. Vaccine hesitancy in the global south: towards a critical perspective on global health. Glob Public Health 2022; 17:1087-98., including vaccines against COVID-19. Then, this study aims to identify, map, and systematize scientific evidence of COVID-19 vaccine hesitancy in Latin American and African countries.

Method

This scoping review seeks to understand broader issues in order to synthesize evidence and map the literature about a field of knowledge that has not yet been fully reviewed or has a complex and heterogeneous nature ²²22. Peters MDJ, Godfrey CM, Khalil H, McInerney P, Parker D, Soares CB. Guidance for conducting systematic scoping reviews. Int J Evid Based Healthc 2015; 13:141-6.^,2323. Tricco AC, Lillie E, Zarin W, O’Brien KK, Colquhoun H, Levac D, et al. PRISMA Extension for Scoping Reviews (PRISMA-ScR): checklist and explanation. Ann Intern Med 2018; 169:467-73.. This study is based on the following question: How has the scientific literature addressed COVID-19 vaccine hesitancy in Latin American and African countries?

This scoping review reporting was structured according to the PRISMA for Scoping Reviews (PRISMA-ScR) checklist items ²²22. Peters MDJ, Godfrey CM, Khalil H, McInerney P, Parker D, Soares CB. Guidance for conducting systematic scoping reviews. Int J Evid Based Healthc 2015; 13:141-6.^,2323. Tricco AC, Lillie E, Zarin W, O’Brien KK, Colquhoun H, Levac D, et al. PRISMA Extension for Scoping Reviews (PRISMA-ScR): checklist and explanation. Ann Intern Med 2018; 169:467-73.: title, structured summary, rationale, objectives, methods (review protocol, eligibility criteria, information sources, search, selection of sources of evidence, organization and synthesis of results), results (selection of evidence, characteristics, appraisal, presentation, and synthesis of results), discussion according to critical global health perspective, study limitations, and final considerations.

Studies in English, Portuguese, and Spanish published from January 1st, 2020 (year when COVID-19 was considered a Public Health Emergency of International Concern by the WHO) to January 22, 2022 were included in this review. A search was conducted in PubMed, Scopus, Web of Science, and Virtual Health Library (VHL) databases. Eligibility criteria included complete empirical, qualitative, quantitative, mixed methods research studies that explicitly and implicitly include COVID-19 vaccine hesitancy in their results, indicating outcomes of acceptance or not, performed with any population in Latin American and African countries, regardless of age group, gender, or other criteria of social differentiation. Publications such as comments, editorials, studies on COVID-19 vaccine development, reviews, studies that did not cover countries in Africa or Latin America, and studies that did not include findings on COVID-19 vaccine hesitancy in their results and discussions were not included.

Searches in the databases were performed in January 2022 using descriptors related to COVID-19, vaccine hesitancy, and countries in Latin America and/or Africa (Supplementary Material: https://cadernos.ensp.fiocruz.br/static//arquivo/suppl-e00041423-en_8375.pdf). Search results were exported to the EndNote (https://endnote.com/) bibliographic reference manager and duplicate studies were excluded. After that, the main author read the titles and abstracts of all studies to exclude those that did not meet the eligibility criteria. In case of any doubt, a second reviewer performed the arbitration by reading the title and abstract, and if doubts persisted, the full study was read.

Three aspects guided the extraction of information in the study reading stage, which were inserted into a Microsoft Excel (https://products.office.com) spreadsheet: (1) General characterization of the studies, including authors, year of publication, journal, country of affiliation, institution of the corresponding author, method aspects (country where the investigation was conducted, study population, objective, and design); (2) Study results regarding acceptance hesitancy, and related reasons; (3) Information of the reference (or not) to the concepts and method references of the WHO SAGE and the context-specific particularities of the Global South reported in the studies. Then, an interpretative analysis of these findings was conducted using the critical perspective in global health regarding vaccine hesitancy ¹⁸18. Montenegro CR, Bernales M, Gonzalez-Aguero M. Teaching global health from the south: challenges and proposals. Crit Public Health 2020; 30:127-9.^,2121. Biehl J, Petryna A. When people come first: critical studies in global health. Princeton: Princeton University Press; 2013..

Results

General characteristics of the studies

After the stages of search and study selection, 94 studies were included in this review. Figure 1 shows a flowchart of these stages.

Regarding the general characteristics of the studies, considering database search was performed in January 2022, most studies were published in 2021 (89), and conducted in African countries (62) followed by Latin American countries (20). Multicenter studies (12) were the most predominant design. Regarding the countries of affiliation, in African studies, most common countries producing university studies were Ethiopia (14), Nigeria (14), Ghana (7), South Africa (6), and Egypt (6). In Latin America, the Brazilian institutions were more commonly found (6). However, some publications had corresponding authors linked with institutions in the United Arab Emirates (3) and France (2). Multicenter studies had corresponding authors affiliated with institutions from countries in the Global North - the United States (6), Belgium (2), and the United Kingdom (2). Box 1 shows the studies selected for this review.

Regarding the study method, most were quantitative studies (85), followed by mixed methods studies (7) and, finally, qualitative studies (2). As for the study population, most were general population (45), followed by health professionals (24), university students (9), individuals with comorbidities (8), health students and professionals (2), university employees and students (1), parents and/or caregivers of children and/or adolescents (4), and population over 50 years old (1).

COVID-19 vaccine acceptance and hesitancy in a comparative perspective

As the results of studies according to acceptance, hesitancy, and related reasons, most studies presented data of COVID-19 vaccine acceptance (88).

A study conducted across the African continent found population acceptance of 63% ²⁴24. Anjorin AAA, Odetokun IA, Abioye AI, Elnadi H, Umoren MV, Damaris BF, et al. Will Africans take COVID-19 vaccination? PLoS One 2021; 16:e0260575.. In Nigeria, studies reported the highest acceptance of 88.5% ²⁵25. Kanyanda S, Markhof Y, Wollburg P, Zezza A. Acceptance of COVID-19 vaccines in Sub-Saharan Africa: evidence from six national phone surveys. BMJ Open 2021; 11:e055159. and the lowest acceptance of 22.7% ²⁶26. Adigwe OP. COVID-19 vaccine hesitancy and willingness to pay: emergent factors from a cross-sectional study in Nigeria. Vaccine X 2021; 9:100112.. In South Africa, studies reported acceptance ranging from 81.6% ²⁷27. Lazarus JV, Wyka K, Rauh L, Rabin K, Ratzan S, Gostin LO, et al. Hesitant or not? The association of age, gender, and education with potential acceptance of a COVID-19 vaccine: a country-level analysis. J Health Commun 2020; 25:799-807. to 55% ²⁸28. Kollamparambil U, Oyenubi A, Nwosu C. COVID19 vaccine intentions in South Africa: health communication strategy to address vaccine hesitancy. BMC Public Health 2021; 21:2113.. In Egypt, the highest acceptance was 32.85% ²⁹29. Elsayed M, El-Abasiri RA, Dardeer KT, Kamal MA, Htay MNN, Abler B, et al. Factors influencing decision making regarding the acceptance of the COVID-19 vaccination in Egypt: a cross-sectional study in an urban, well-educated sample. Vaccines (Basel) 2022; 10:20. and the lowest, 21% ³⁰30. Fares S, Elmnyer MM, Mohamed SS, Elsayed R. COVID-19 vaccination perception and attitude among healthcare workers in Egypt. J Prim Care Community Health 2021; 12:21501327211013303.. In Ethiopia, the highest acceptance was 97.9% ²⁵25. Kanyanda S, Markhof Y, Wollburg P, Zezza A. Acceptance of COVID-19 vaccines in Sub-Saharan Africa: evidence from six national phone surveys. BMJ Open 2021; 11:e055159. and the lowest, 45.5% ³¹31. Mesele M. COVID-19 vaccination acceptance and its associated factors in Sodo Town, Wolaita Zone, Southern Ethiopia: cross-sectional study. Infect Drug Resist 2021; 14:2361-7.. In Ghana, acceptance ranged from 64.72% ³²32. Alhassan RK, Aberese-Ako M, Doegah PT, Immurana M, Dalaba MA, Manyeh AK, et al. COVID-19 vaccine hesitancy among the adult population in Ghana: evidence from a pre-vaccination rollout survey. Trop Med Health 2021; 49:96. to 35% ³³33. Yeboah P, Daliri DB, Abdin AY, Appiah-Brempong E, Pitsch W, Panyin AB, et al. Knowledge into the practice against COVID-19: a cross-sectional study from Ghana. Int J Environ Res Public Health 2021; 18:12902.. In Libya, acceptance ranged from 79.6% to 41.2%, depending on the vaccine efficacy ³⁴34. Elhadi M, Alsoufi A, Alhadi A, Hmeida A, Alshareea E, Dokali M, et al. Knowledge, attitude, and acceptance of healthcare workers and the public regarding the COVID-19 vaccine: a cross-sectional study. BMC Public Health 2021; 21:955.. Mozambique reported 71.4% acceptance ³⁵35. Dula J, Mulhanga A, Nhanombe A, Cumbi L, Júnior A, Gwatsvaira J, et al. COVID-19 vaccine acceptability and its determinants in Mozambique: an online survey. Vaccines (Basel) 2021; 9:828.. In Burkina Faso, acceptance was 79.6% ²⁵25. Kanyanda S, Markhof Y, Wollburg P, Zezza A. Acceptance of COVID-19 vaccines in Sub-Saharan Africa: evidence from six national phone surveys. BMJ Open 2021; 11:e055159.. In the Democratic Republic of the Congo, the highest and lowest acceptance rates were 59.4% and 32.9% ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.. In Somalia, acceptance was 76.8% ³⁷37. Ahmed MAM, Colebunders R, Gele AA, Farah AA, Osman S, Guled IA, et al. COVID-19 vaccine acceptability and adherence to preventive measures in Somalia: results of an online survey. Vaccines (Basel) 2021; 9:543.. In Uganda, depending on the vaccine efficacy, acceptance was 88.8% and 65.4% ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.. Acceptance in Benin was 48.4% and 22.6%, depending on the vaccine efficacy ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.. Malawi had acceptance of 61.7% and 44.4%, depending on the vaccine efficacy ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.. In Mali, it ranged from 74.5% to 45.5%, depending on the vaccine efficacy ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515..

In Latin American countries, the highest and lowest acceptance rates were 94.2% ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515. and 66% ³⁸38. Ticona JPA, Nery N, Victoriano R, Fofana MO, Ribeiro GS, Giorgi E, et al. Willingness to get the COVID-19 vaccine among residents of slum settlements. Vaccines (Basel) 2021; 9:951. in Brazil. In Ecuador, vaccine acceptance ranged from 91% to 27%, depending on the vaccine efficacy ¹⁴14. Jaramillo-Monge J, Obimpeh M, Vega B, Acurio D, Boven A, Verhoeven V, et al. COVID-19 vaccine acceptance in Azuay Province, Ecuador: a cross-sectional online survey. Vaccines (Basel) 2021; 9:678.. In Chile, acceptance was 49% ³⁹39. Cerda AA, García LY. Hesitation and refusal factors in individuals' decision-making processes regarding a coronavirus disease 2019 vaccination. Front Public Health 2021; 9:626852., and in Colombia acceptance ranged from 71.56% to 57.23% ⁴⁰40. Stojanovic J, Boucher VG, Gagne M, Gupta S, Joyal-Desmarais K, Paduano S, et al. Global trends and correlates of COVID-19 vaccination hesitancy: findings from the iCARE study. Vaccines (Basel) 2021; 9:661.. In Peru, vaccine acceptance was 70.4% ⁴¹41. Vizcardo D, Salvador LF, Nole-Vara A, Dávila KP, Alvarez-Risco A, Yáñez JA, et al. Sociodemographic predictors associated with the willingness to get vaccinated against COVID-19 in Peru: a cross-sectional survey. Vaccines (Basel) 2022; 10:48., and 71.25% in Venezuela ⁴²42. Andrade G. Covid-19 vaccine hesitancy, conspiracist beliefs, paranoid ideation and perceived ethnic discrimination in a sample of university students in Venezuela. Vaccine 2021; 39:6837-42.^,4343. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5..

Regarding hesitancy and refusal of COVID-19 vaccines in Africa, the highest hesitancy rate was 52.9% ²⁶26. Adigwe OP. COVID-19 vaccine hesitancy and willingness to pay: emergent factors from a cross-sectional study in Nigeria. Vaccine X 2021; 9:100112. and the lowest 25.5% ⁴⁴44. Adebisi YA, Alaran AJ, Bolarinwa OA, Akande-Sholabi W, Lucero-Prisno DE. When it is available, will we take it? Social media users' perception of hypothetical COVID-19 vaccine in Nigeria. Pan Afr Med J 2021; 38:230. in Nigeria. In South Africa, hesitancy was 29.16% ²⁸28. Kollamparambil U, Oyenubi A, Nwosu C. COVID19 vaccine intentions in South Africa: health communication strategy to address vaccine hesitancy. BMC Public Health 2021; 21:2113.. In Egypt, the highest hesitancy rate was 67.15% ²⁹29. Elsayed M, El-Abasiri RA, Dardeer KT, Kamal MA, Htay MNN, Abler B, et al. Factors influencing decision making regarding the acceptance of the COVID-19 vaccination in Egypt: a cross-sectional study in an urban, well-educated sample. Vaccines (Basel) 2022; 10:20. and the lowest, 28% ³⁰30. Fares S, Elmnyer MM, Mohamed SS, Elsayed R. COVID-19 vaccination perception and attitude among healthcare workers in Egypt. J Prim Care Community Health 2021; 12:21501327211013303.. In Ethiopia, the highest hesitancy rate was 54.5% ³¹31. Mesele M. COVID-19 vaccination acceptance and its associated factors in Sodo Town, Wolaita Zone, Southern Ethiopia: cross-sectional study. Infect Drug Resist 2021; 14:2361-7. and the lowest, 6.61% ⁴⁵45. Oyekale AS. Willingness to take COVID-19 vaccines in Ethiopia: an instrumental variable probit approach. Int J Environ Res Public Health 2021; 18:8892.^,4646. Oyekale AS. Compliance indicators of COVID-19 prevention and vaccines hesitancy in Kenya: a random-effects endogenous probit model. Vaccines (Basel) 2021; 9:1359.. Burkina Faso had 53.7% refusal ²⁵25. Kanyanda S, Markhof Y, Wollburg P, Zezza A. Acceptance of COVID-19 vaccines in Sub-Saharan Africa: evidence from six national phone surveys. BMJ Open 2021; 11:e055159.. In Ghana, the highest refusal was 35.28% ³²32. Alhassan RK, Aberese-Ako M, Doegah PT, Immurana M, Dalaba MA, Manyeh AK, et al. COVID-19 vaccine hesitancy among the adult population in Ghana: evidence from a pre-vaccination rollout survey. Trop Med Health 2021; 49:96. and the lowest, 21% ¹¹11. Acheampong T, Akorsikumah EA, Osae-Kwapong J, Khalid M, Appiah A, Amuasi JH. Examining vaccine hesitancy in Sub-Saharan Africa: a survey of the knowledge and attitudes among adults to receive COVID-19 vaccines in Ghana. Vaccines (Basel) 2021; 9:814.. In Libya, refusal ranged from 58.8% to 20.4%, depending on the vaccine efficacy ³⁴34. Elhadi M, Alsoufi A, Alhadi A, Hmeida A, Alshareea E, Dokali M, et al. Knowledge, attitude, and acceptance of healthcare workers and the public regarding the COVID-19 vaccine: a cross-sectional study. BMC Public Health 2021; 21:955.. Mozambique had 28.6% refusal rate ³⁵35. Dula J, Mulhanga A, Nhanombe A, Cumbi L, Júnior A, Gwatsvaira J, et al. COVID-19 vaccine acceptability and its determinants in Mozambique: an online survey. Vaccines (Basel) 2021; 9:828..

In Latin American countries, the highest vaccine hesitancy rate of 26.1% ³⁸38. Ticona JPA, Nery N, Victoriano R, Fofana MO, Ribeiro GS, Giorgi E, et al. Willingness to get the COVID-19 vaccine among residents of slum settlements. Vaccines (Basel) 2021; 9:951. and the lowest 8.4% ⁴⁰40. Stojanovic J, Boucher VG, Gagne M, Gupta S, Joyal-Desmarais K, Paduano S, et al. Global trends and correlates of COVID-19 vaccination hesitancy: findings from the iCARE study. Vaccines (Basel) 2021; 9:661. were reported in Brazil. In Ecuador, hesitancy ranged from 73% to 9%, depending on the vaccine efficacy ¹⁴14. Jaramillo-Monge J, Obimpeh M, Vega B, Acurio D, Boven A, Verhoeven V, et al. COVID-19 vaccine acceptance in Azuay Province, Ecuador: a cross-sectional online survey. Vaccines (Basel) 2021; 9:678.. In Chile, 28% were hesitant ³⁹39. Cerda AA, García LY. Hesitation and refusal factors in individuals' decision-making processes regarding a coronavirus disease 2019 vaccination. Front Public Health 2021; 9:626852. and 23% refused the vaccine ³⁹39. Cerda AA, García LY. Hesitation and refusal factors in individuals' decision-making processes regarding a coronavirus disease 2019 vaccination. Front Public Health 2021; 9:626852.. Peru had 10.1% refusal and 19.5% hesitancy ⁴¹41. Vizcardo D, Salvador LF, Nole-Vara A, Dávila KP, Alvarez-Risco A, Yáñez JA, et al. Sociodemographic predictors associated with the willingness to get vaccinated against COVID-19 in Peru: a cross-sectional survey. Vaccines (Basel) 2022; 10:48.. In Venezuela, vaccine hesitancy was 28.75% ⁴³43. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5.. Figure 2 shows a map with the highest percentages of COVID-19 vaccine hesitancy reported in selected studies.

The reasons for COVID-19 vaccine hesitancy were explored in 84 of total 94 studies (Box 2). The other studies did not specify the reasons in their results. The main reasons were: concern about possible adverse events (47.8%), safety issues of COVID-19 vaccines (31.9%), uncertainty about COVID-19 vaccine efficacy (34%), conspiracy theories (21.2%), lack of reliability in clinical trials/rapid vaccine development (15.9%), perception of the immune system as a better defense against COVID-19 than the vaccine (14.8%); religious beliefs (10.6%), lack of information about vaccines (10.6%), risk of contracting COVID-19 considered low (7.4%), being against vaccines in general (6.3%), vaccine cost (6.3%), and freedom of choice (2.1%).

Particularities of vaccine hesitancy in the Global South

Although most studies are focused on quantitative data, some publications describe specificities in the Global South regarding vaccine hesitancy in social, cultural, political, and economic dimensions.

In the study conducted by Andrade ⁴²42. Andrade G. Covid-19 vaccine hesitancy, conspiracist beliefs, paranoid ideation and perceived ethnic discrimination in a sample of university students in Venezuela. Vaccine 2021; 39:6837-42.^,4343. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5., religious factors influenced vaccine hesitancy in Venezuela, where belief in conspiracy theories has increased with the country’s political instability. Also, non-religious participants were more willing to receive the COVID-19 vaccine than Catholic and Protestant participants, with Venezuelan Pentecostals as the most hesitant religious group regarding COVID-19 vaccines.

Regarding political factors, studies conducted in Brazil and Venezuela mentioned opposition to the vaccine of their respective presidents Jair Bolsonaro and Nicolás Maduro ⁴²42. Andrade G. Covid-19 vaccine hesitancy, conspiracist beliefs, paranoid ideation and perceived ethnic discrimination in a sample of university students in Venezuela. Vaccine 2021; 39:6837-42.^,4343. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5.^,4747. Chaves IES, Brito PRP, de Araújo Rodrigues JGB, Costa MS, Cândido EL, Moreira MRC. Hesitation regarding the COVID-19 vaccine among medical students in Brazil. Rev Assoc Med Bras 2021; 67:1397-402.^,4848. Gramacho WG, Turgeon M. When politics collides with public health: COVID-19 vaccine country of origin and vaccination acceptance in Brazil. Vaccine 2021; 39:2608-12.^,4949. Paschoalotto MAC, Costa EPPA, De Almeida SV, Cima J, da Costa JG, Santos JV, et al. Running away from the jab: factors associated with COVID-19 vaccine hesitancy in Brazil. Rev Saúde Pública 2021; 55:97.. Maduro questioned the safety of the AstraZeneca vaccine, even refusing to buy it, and because his government was not recognized by many nations ⁴²42. Andrade G. Covid-19 vaccine hesitancy, conspiracist beliefs, paranoid ideation and perceived ethnic discrimination in a sample of university students in Venezuela. Vaccine 2021; 39:6837-42.^,4343. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5.. In Brazil, part of supporters of then President Jair Bolsonaro rejected the COVID-19 vaccine, based on Bolsonaro’s speech in relation to the vaccine as an individual choice and the criticism to the Sinovac-CoronaVac vaccine, produced by a Chinese pharmaceutical company ⁴⁷47. Chaves IES, Brito PRP, de Araújo Rodrigues JGB, Costa MS, Cândido EL, Moreira MRC. Hesitation regarding the COVID-19 vaccine among medical students in Brazil. Rev Assoc Med Bras 2021; 67:1397-402.^,4848. Gramacho WG, Turgeon M. When politics collides with public health: COVID-19 vaccine country of origin and vaccination acceptance in Brazil. Vaccine 2021; 39:2608-12.^,4949. Paschoalotto MAC, Costa EPPA, De Almeida SV, Cima J, da Costa JG, Santos JV, et al. Running away from the jab: factors associated with COVID-19 vaccine hesitancy in Brazil. Rev Saúde Pública 2021; 55:97.. The negative perception of coping with COVID-19 and the political opposition to the Federal Government were associated with the intention to be vaccinated ⁴⁹49. Paschoalotto MAC, Costa EPPA, De Almeida SV, Cima J, da Costa JG, Santos JV, et al. Running away from the jab: factors associated with COVID-19 vaccine hesitancy in Brazil. Rev Saúde Pública 2021; 55:97., in addition to the political context of delay in the acquisition and availability of COVID-19 vaccines and political disputes between federal and state governments ⁴⁷47. Chaves IES, Brito PRP, de Araújo Rodrigues JGB, Costa MS, Cândido EL, Moreira MRC. Hesitation regarding the COVID-19 vaccine among medical students in Brazil. Rev Assoc Med Bras 2021; 67:1397-402.^,4949. Paschoalotto MAC, Costa EPPA, De Almeida SV, Cima J, da Costa JG, Santos JV, et al. Running away from the jab: factors associated with COVID-19 vaccine hesitancy in Brazil. Rev Saúde Pública 2021; 55:97..

The categories of race and ethnicity also influenced vaccine hesitancy - in Venezuela, marginalized ethnic minorities were more likely to present COVID-19 vaccine hesitancy ⁴²42. Andrade G. Covid-19 vaccine hesitancy, conspiracist beliefs, paranoid ideation and perceived ethnic discrimination in a sample of university students in Venezuela. Vaccine 2021; 39:6837-42.^,4343. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5.. In South Africa, the black population showed lower vaccine hesitancy (26%) ²⁸28. Kollamparambil U, Oyenubi A, Nwosu C. COVID19 vaccine intentions in South Africa: health communication strategy to address vaccine hesitancy. BMC Public Health 2021; 21:2113..

Regarding differences in vaccine hesitancy between urban and rural areas, findings from studies conducted in Zambia, South Africa, the Democratic Republic of the Congo, and Ghana showed that vaccine hesitancy was higher in urban areas with more access to the Internet and, consequently, to social media and misinformation about COVID-19 vaccines when compared to rural areas ²⁸28. Kollamparambil U, Oyenubi A, Nwosu C. COVID19 vaccine intentions in South Africa: health communication strategy to address vaccine hesitancy. BMC Public Health 2021; 21:2113.^,3232. Alhassan RK, Aberese-Ako M, Doegah PT, Immurana M, Dalaba MA, Manyeh AK, et al. COVID-19 vaccine hesitancy among the adult population in Ghana: evidence from a pre-vaccination rollout survey. Trop Med Health 2021; 49:96.^,5050. Carcelen AC, Prosperi C, Mutembo S, Chongwe G, Mwansa FD, Ndubani P, et al. COVID-19 vaccine hesitancy in Zambia: a glimpse at the possible challenges ahead for COVID-19 vaccination rollout in sub-Saharan Africa. Hum Vaccin Immunother 2022; 18:1-6.^,5151. Ditekemena JD, Nkamba DM, Mutwadi A, Mavoko HM, Fodjo JNS, Luhata C, et al. COVID-19 vaccine acceptance in the Democratic Republic of Congo: a cross-sectional survey. Vaccines (Basel) 2021; 9:153.. In Nigeria, the population living in the south of the country was more likely to be vaccinated while the population in the north was more likely to refuse it ²⁴24. Anjorin AAA, Odetokun IA, Abioye AI, Elnadi H, Umoren MV, Damaris BF, et al. Will Africans take COVID-19 vaccination? PLoS One 2021; 16:e0260575.. Then, strategies to reduce vaccine hesitancy must consider regional aspects of each African territory ²⁴24. Anjorin AAA, Odetokun IA, Abioye AI, Elnadi H, Umoren MV, Damaris BF, et al. Will Africans take COVID-19 vaccination? PLoS One 2021; 16:e0260575.. In Latin America, the intention to be vaccinated in Peru and Brazil was lower in areas of greater social inequality ³⁸38. Ticona JPA, Nery N, Victoriano R, Fofana MO, Ribeiro GS, Giorgi E, et al. Willingness to get the COVID-19 vaccine among residents of slum settlements. Vaccines (Basel) 2021; 9:951.^,4141. Vizcardo D, Salvador LF, Nole-Vara A, Dávila KP, Alvarez-Risco A, Yáñez JA, et al. Sociodemographic predictors associated with the willingness to get vaccinated against COVID-19 in Peru: a cross-sectional survey. Vaccines (Basel) 2022; 10:48..

Some epidemiological studies revealed that women were more likely to hesitate to accept COVID-19 vaccine in African countries ²⁴24. Anjorin AAA, Odetokun IA, Abioye AI, Elnadi H, Umoren MV, Damaris BF, et al. Will Africans take COVID-19 vaccination? PLoS One 2021; 16:e0260575.^,2525. Kanyanda S, Markhof Y, Wollburg P, Zezza A. Acceptance of COVID-19 vaccines in Sub-Saharan Africa: evidence from six national phone surveys. BMJ Open 2021; 11:e055159.^,2828. Kollamparambil U, Oyenubi A, Nwosu C. COVID19 vaccine intentions in South Africa: health communication strategy to address vaccine hesitancy. BMC Public Health 2021; 21:2113.^,3232. Alhassan RK, Aberese-Ako M, Doegah PT, Immurana M, Dalaba MA, Manyeh AK, et al. COVID-19 vaccine hesitancy among the adult population in Ghana: evidence from a pre-vaccination rollout survey. Trop Med Health 2021; 49:96.^,3636. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.^,3737. Ahmed MAM, Colebunders R, Gele AA, Farah AA, Osman S, Guled IA, et al. COVID-19 vaccine acceptability and adherence to preventive measures in Somalia: results of an online survey. Vaccines (Basel) 2021; 9:543.^,5252. Agyekum MW, Afrifa-Anane GF, Kyei-Arthur F, Addo B. Acceptability of COVID-19 vaccination among health care workers in Ghana. Adv Public Heath 2021; 2021:9998176.^,5353. Bongomin F, Olum R, Andia-Biraro I, Nakwagala FN, Hassan KH, Nassozi DR, et al. COVID-19 vaccine acceptance among high-risk populations in Uganda. Ther Adv Infect Dis 2021; 8:20499361211024376.^,5454. Iliyasu Z, Garba MR, Gajida AU, Amole TG, Umar AA, Abdullahi HM, et al. ‘Why should I take the COVID-19 vaccine after recovering from the disease?’ A mixed-methods study of correlates of COVID-19 vaccine acceptability among health workers in Northern Nigeria. Pathog Glob Health 2021; 116:254-62. due to possible access to misinformation, such as the rumor that COVID-19 vaccine could make a person sterile ³⁷37. Ahmed MAM, Colebunders R, Gele AA, Farah AA, Osman S, Guled IA, et al. COVID-19 vaccine acceptability and adherence to preventive measures in Somalia: results of an online survey. Vaccines (Basel) 2021; 9:543..

In Africa, the history of resistance to vaccination and growing misinformation disseminated via social media by leaders and religious groups about vaccines in general, including COVID-19 vaccines, were addressed in some studies ³²32. Alhassan RK, Aberese-Ako M, Doegah PT, Immurana M, Dalaba MA, Manyeh AK, et al. COVID-19 vaccine hesitancy among the adult population in Ghana: evidence from a pre-vaccination rollout survey. Trop Med Health 2021; 49:96.^,3636. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.^,5151. Ditekemena JD, Nkamba DM, Mutwadi A, Mavoko HM, Fodjo JNS, Luhata C, et al. COVID-19 vaccine acceptance in the Democratic Republic of Congo: a cross-sectional survey. Vaccines (Basel) 2021; 9:153.^,5555. Alhassan RK, Owusu-Agyei S, Ansah EK, Gyapong M. COVID-19 vaccine uptake among health care workers in Ghana: a case for targeted vaccine deployment campaigns in the global south. Hum Resour Health 2021; 19:136.^,5656. Lamptey E, Serwaa D, Appiah AB. A nationwide survey of the potential acceptance and determinants of COVID-19 vaccines in Ghana. Clin Exp Vaccine Res 2021; 10:183-90.^,5757. Mustapha M, Lawal BK, Sha’aban A, Jatau AI, Wada AS, Bala AA, et al. Factors associated with acceptance of COVID-19 vaccine among university health sciences students in Northwest Nigeria. PLoS One 2021; 16:e0260672.. The lack of clear information about the disease and vaccines were factors that influenced hesitancy in Ethiopia and the Democratic Republic of the Congo - with public distrust in participating in COVID-19 vaccine tests in the Democratic Republic of the Congo ⁵¹51. Ditekemena JD, Nkamba DM, Mutwadi A, Mavoko HM, Fodjo JNS, Luhata C, et al. COVID-19 vaccine acceptance in the Democratic Republic of Congo: a cross-sectional survey. Vaccines (Basel) 2021; 9:153.^,5858. Shiferie F, Sada O, Fenta T, Kaba M, Fentie AM. Exploring reasons for COVID-19 vaccine hesitancy among healthcare providers in Ethiopia. Pan Afr Med J 2021; 40:213.. Another factor that influenced vaccine hesitancy in African countries was the lower mortality from COVID-19 in these countries, due to the perception that the continent had a reduced risk of COVID-19, as in the case of Ghana and Uganda ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.^,5959. Botwe BO, Antwi WK, Adusei JA, Mayeden RN, Akudjedu TN, Sule SD. COVID-19 vaccine hesitancy concerns: findings from a Ghana clinical radiography workforce survey. Radiography (Lond) 2022; 28:537-44.^,6060. Kanyike AM, Olum R, Kajjimu J, Ojilong D, Akech GM, Nassozi DR, et al. Acceptance of the coronavirus disease-2019 vaccine among medical students in Uganda. Trop Med Health 2021; 49:37..

Two studies conducted in Brazil obtained a low percentage of COVID-19 vaccine hesitancy and a higher percentage of acceptance among respondents ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.^,6161. Bagateli LE, Saeki EY, Fadda M, Agostoni C, Marchisio P, Milani GP. COVID-19 vaccine hesitancy among parents of children and adolescents living in Brazil. Vaccines (Basel) 2021; 9:1115.. According to these studies, the result is influenced by the high transmission and mortality rates of COVID-19 ³⁶36. Bono SA, Villela EFM, Siau CS, Chen WS, Pengpid S, Hasan MT, et al. Factors affecting COVID-19 vaccine acceptance: an international survey among low- and middle-income countries. Vaccines (Basel) 2021; 9:515.^,6161. Bagateli LE, Saeki EY, Fadda M, Agostoni C, Marchisio P, Milani GP. COVID-19 vaccine hesitancy among parents of children and adolescents living in Brazil. Vaccines (Basel) 2021; 9:1115.. However, another publication claims that hesitant participants did not understand or were not informed about the high risk of COVID-19 in Brazil ⁶²62. Macinko J, Seixas BV, De Melo Mambrini JV, Lima-Costa MF. Which older Brazilians will accept a COVID-19 vaccine? Cross-sectional evidence from the Brazilian Longitudinal Study of Aging (ELSI-Brazil). BMJ Open 2021; 11:e049928..

The third aspects of this analysis emphasized the influence of the WHO SAGE group as a reference for designing epidemiological studies on vaccine hesitancy. The report produced by the group ⁵5. World Health Organization. Report of the SAGE Working Group on Vaccine Hesitancy. Geneva: World Health Organization; 2014.^,66. World Health Organization. Appendices to Report of the SAGE working group on vaccine hesitancy. Geneva: World Health Organization; 2014. and the publication by Larson et al. ⁶³63. Larson HJ, Jarrett C, Schulz WS, Chaudhuri M, Zhou Y, Dube E, et al. Measuring vaccine hesitancy: the development of a survey tool. Vaccine 2015; 33:4165-75. presents tools to measure and monitor vaccine hesitancy such as the Vaccine Hesitancy Scale (VHS). Despite this effort, most epidemiological studies (88) did not use references, method designs, and instruments developed by the WHO SAGE.

Regarding the term “vaccine hesitancy”, 61 of the 94 studies mention it without referring to the WHO and 26 studies use the WHO definition in the introduction of the study, but do not discuss the results according to the WHO SAGE framework. One exception is the study by Anjorin et al. ²⁴24. Anjorin AAA, Odetokun IA, Abioye AI, Elnadi H, Umoren MV, Damaris BF, et al. Will Africans take COVID-19 vaccination? PLoS One 2021; 16:e0260575., conducted across the African continent, and whose corresponding author is affiliated with a research institution in South Africa. It provided the definition of vaccine hesitancy and used the 3C model as a reference to discuss the results. According to this study, the perceived risk of SARS-CoV-2 is significantly related to vaccine hesitancy; therefore, the authors concluded the findings agree with the model of confidence, complacency, and convenience proposed by the WHO SAGE ²⁴24. Anjorin AAA, Odetokun IA, Abioye AI, Elnadi H, Umoren MV, Damaris BF, et al. Will Africans take COVID-19 vaccination? PLoS One 2021; 16:e0260575..

Among the studies that used the scale or developed research instruments based on WHO SAGE publications (6), a study conducted in Ethiopia used a questionnaire to assess vaccine hesitancy of the participants according to the WHO definition ⁶⁴64. Angelo AT, Alemayehu DS, Dachew AM. Health care workers intention to accept COVID-19 vaccine and associated factors in southwestern Ethiopia, 2021. PLoS One 2021; 16:e0257109.. The WHO Matrix of Vaccine Hesitancy Determinants (contextual, individual/group determinants, and specific issues about vaccine/vaccination) was used in three studies - one in Brazil ⁴⁷47. Chaves IES, Brito PRP, de Araújo Rodrigues JGB, Costa MS, Cândido EL, Moreira MRC. Hesitation regarding the COVID-19 vaccine among medical students in Brazil. Rev Assoc Med Bras 2021; 67:1397-402., one in Cameroon ⁶⁵65. Dinga JN, Sinda LK, Titanji VPK. Assessment of vaccine hesitancy to a COVID-19 vaccine in Cameroonian adults and its global implication. Vaccines (Basel) 2021; 9:175., and one in Egypt ³⁰30. Fares S, Elmnyer MM, Mohamed SS, Elsayed R. COVID-19 vaccination perception and attitude among healthcare workers in Egypt. J Prim Care Community Health 2021; 12:21501327211013303.. Regarding the 5C questionnaire, a multicenter study conducted in Middle Eastern countries used an adapted version for the Arabic language and culture to investigate the psychological antecedents of COVID-19 vaccination ⁶⁶66. Abdou MS, Kheirallah KA, Aly MO, Ramadan A, Elhadi YAM, Elbarazi I, et al. The coronavirus disease 2019 (COVID-19) vaccination psychological antecedent assessment using the Arabic 5c validated tool: an online survey in 13 Arab countries. PLoS One 2021; 16:e0260321.. A multicenter study in Asia, Africa, and South America used the VHS to measure the belief in the benefits of vaccination and the perceived risk of new vaccines ⁶⁷67. Harapan H, Anwar S, Yufika A, Sharun K, Gachabayov M, Fahriani M, et al. Vaccine hesitancy among communities in ten countries in Asia, Africa, and South America during the COVID-19 pandemic. Pathog Glob Health 2022; 116:236-43.. All these studies had corresponding authors affiliated with institutions in the Global South.

Discussion

COVID-19 vaccine hesitancy can be an obstacle to reducing the effects of the pandemic. The findings of this review show that concern about possible adverse events, uncertainty about vaccine efficacy and safety, and lack of confidence in clinical trials for the development of COVID-19 vaccines were similar to other studies ¹⁶16. Biswas MR, Alzubaidi MS, Shah U, Abd-Alrazaq AA, Shah Z. A scoping review to find out worldwide COVID-19 vaccine hesitancy and its underlying determinants. Vaccines (Basel) 2021; 9:1243.^,1717. Aw J, Seng JJ, Seah SS, Low LL. COVID-19 vaccine hesitancy: a scoping review of literature in high-income countries. Vaccines (Basel) 2021; 9:900.^,6868. Majid U, Ahmad M, Zain S, Akande A, Ikhlaq F. COVID-19 vaccine hesitancy and acceptance: a comprehensive scoping review of global literature. Health Promot Int 2022; 37:daac078.^,6969. Soares P, Rocha JV, Moniz M, Gama A, Laires PA, Pedro AR, et al. Factors associated with COVID-19 vaccine hesitancy. Vaccines (Basel) 2021; 9:300.. Considering the phenomenon of hesitancy is multidimensional, the main justifications for hesitancy involve factors that go beyond biomedical biases to include sociocultural aspects with dichotomies such as medical/scientific view vs. cultural/popular view and universality vs. singularity ⁷⁰70. Moulin AM. A hipótese vacinal: por uma abordagem crítica e antropológica de um fenômeno histórico. Hist Ciênc Saúde-Manguinhos 2003; 10:499-517.. This scenario became even more complex with the advent of COVID-19, with the resurgence of movements of disbelief in science, dissemination of fake news about vaccines, ideological polarization, and socioeconomic vulnerability ⁹9. Matos CCSA, Gonçalves BA, Couto MT. Vaccine hesitancy in the global south: towards a critical perspective on global health. Glob Public Health 2022; 17:1087-98..

The strong association between the political scenario and (non-)acceptance of vaccines is also reflected in COVID-19 vaccines. In this review, political instability, disbelief in the government and the health system, and the feeling of not having a voice or power in the face of structures such as the State itself, have a direct influence on the spread of conspiracy theories ⁷¹71. Handy LK, Maroudi S, Powell M, Nfila B, Moser C, Japa I, et al. The impact of access to immunization information on vaccine acceptance in three countries. PLoS One 2017; 12:e0180759.^,7272. van Prooijen J-W. Populism as political mentality underlying conspiracy theories. In: Rutjens B, Brandt M, editors. Belief systems and the perception of reality. New York: Taylor and Francis; 2019. p. 79-96. (Series: Current Issues in Social Psychology).. On the other hand, it is important to critically analyze the scenario in which these conspiracy theories were created, as many of them have concrete roots in the recent local history of these territories.

Underdeveloped countries were repeatedly used for tests with human beings, which today resulted in vaccine refusal due to the fear of being laboratory subjects ⁷³73. Démolis R, Botão C, Heyerdahl LW, Gessner BD, Cavailler P, Sinai C, et al. A rapid qualitative assessment of oral cholera vaccine anticipated acceptability in a context of resistance towards cholera intervention in Nampula, Mozambique. Vaccine 2018; 36:6497-505.^,7474. Wiyeh AB, Cooper S, Jaca A, Mavundza E, Ndwandwe D, Wiysonge CS. Social media and HPV vaccination: unsolicited public comments on a Facebook post by the Western Cape Department of Health provide insights into determinants of vaccine hesitancy in South Africa. Vaccine 2019; 37:6317-23.. The power relationship between the Global North and the Global South, expressed in a past of coloniality and violence still alive in the memory of colonized countries, is reflected in the rejection of practices that supposedly come from the North. Then vaccines are seen by different groups as population control strategies in underdeveloped countries, as “western malevolence”, or as a method to extinguish undesirable groups ⁷⁵75. Heyerdahl LW, Pugliese-Garcia M, Nkwemu S, Tembo T, Mwamba C, Demolis R, et al. “It depends how one understands it”: a qualitative study on differential uptake of oral cholera vaccine in three compounds in Lusaka, Zambia. BMC Infect Dis 2019; 19:421.^,7676. Kpanake L, Sorum PC, Mullet E. Willingness to get vaccinated against Ebola: a mapping of Guinean people positions. Hum Vaccin Immunother 2018; 14:2391-6.^,7777. Morhason-Bello IO, Wallis S, Adedokun BO, Adewole IF. Willingness of reproductive-aged women in a Nigerian community to accept human papillomavirus vaccination for their children. J Obstet Gynaecol Res 2015; 41:1621-9.^,7878. Turiho AK, Okello ES, Muhwezi WW, Katahoire AR. Perceptions of human papillomavirus vaccination of adolescent schoolgirls in western Uganda and their implications for acceptability of HPV vaccination: a qualitative study. BMC Res Notes 2017; 10:431.. Therefore, discussions that associate the low level of vaccine acceptance in Africa with the fact that Africa had lower COVID-19 mortality rates or more misinformation may lead to reductionisms ⁹9. Matos CCSA, Gonçalves BA, Couto MT. Vaccine hesitancy in the global south: towards a critical perspective on global health. Glob Public Health 2022; 17:1087-98..

On the other hand, associating low percentages of vaccine hesitancy with countries that had many COVID-19 cases and deaths may also disregard local contexts. This review, for example, found that many studies highlighted high acceptance of vaccine in Brazil, establishing this association. However, Brazil is internationally recognized for its National Immunization Program, which has built a culture of collective immunization ⁷⁹79. Hochman G. Vacinação, varíola e uma cultura da imunização no Brasil. Ciênc Saúde Colet 2011; 16:375-86.^,8080. Organização Pan-Americana da Saúde. Relatório 30 anos de SUS, que SUS para 2030? Brasília: Organização Pan-Americana da Saúde; 2018.. At the same time, like other Latin American countries - as seen in this review - the country had to handle political instability, mismanagement of the COVID-19 pandemic, denial speeches by the president of the republic, and well-grounded direct association between “being opposed to the government” and “intention to be vaccinated” ⁴⁷47. Chaves IES, Brito PRP, de Araújo Rodrigues JGB, Costa MS, Cândido EL, Moreira MRC. Hesitation regarding the COVID-19 vaccine among medical students in Brazil. Rev Assoc Med Bras 2021; 67:1397-402.^,4848. Gramacho WG, Turgeon M. When politics collides with public health: COVID-19 vaccine country of origin and vaccination acceptance in Brazil. Vaccine 2021; 39:2608-12.^,4949. Paschoalotto MAC, Costa EPPA, De Almeida SV, Cima J, da Costa JG, Santos JV, et al. Running away from the jab: factors associated with COVID-19 vaccine hesitancy in Brazil. Rev Saúde Pública 2021; 55:97..

Likewise, as demonstrated in this review, some countries in the Global South still face sanctions from Global North countries, due to the non-recognition of their governments - such as Venezuela ⁴²42. Andrade G. Covid-19 vaccine hesitancy, conspiracist beliefs, paranoid ideation and perceived ethnic discrimination in a sample of university students in Venezuela. Vaccine 2021; 39:6837-42.^,4343. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5.. Then, the power relations are evident between the Global North and the Global South, requiring discussions on low vaccination coverage in these countries from a broad perspective, which does not reduce (non-)vaccination to vaccine hesitancy or lack of information ⁹9. Matos CCSA, Gonçalves BA, Couto MT. Vaccine hesitancy in the global south: towards a critical perspective on global health. Glob Public Health 2022; 17:1087-98.^,8181. Blanchet K, Mallard G, Moret E, Sun J. Sanctioned countries in the global COVID-19 vaccination campaign: the forgotten 70%. Confl Health 2021; 15:69..

Finally, in both Latin America and Africa, religious factors were also relevant in the population’s decision to be or not vaccinated. Religion is a driving factor for vaccine hesitancy in general in the Global South ⁸²82. Abakar MF, Seli D, Lechthaler F, Schelling E, Tran N, Zinsstag J, et al. Vaccine hesitancy among mobile pastoralists in Chad: a qualitative study. Int J Equity Health 2018; 17:167.^,8383. Farouk ZL, Slusher TM, Danzomo AA, Slusher IL. Factors influencing neonatal practice in a rural community in Kano (Northern), Nigeria. J Trop Pediatr 2019; 65:569-75.^,8484. Pugliese-Garcia M, Heyerdahl LW, Mwamba C, Nkwemu S, Chilengi R, Demolis R, et al. Factors influencing vaccine acceptance and hesitancy in three informal settlements in Lusaka, Zambia. Vaccine 2018; 36:5617-24., and this trend was also seen for COVID-19 vaccines ⁴²42. Andrade G. Covid-19 vaccine hesitancy, conspiracist beliefs, paranoid ideation and perceived ethnic discrimination in a sample of university students in Venezuela. Vaccine 2021; 39:6837-42.^,4343. Andrade G. Predictive demographic factors of Covid-19 vaccine hesitancy in Venezuela: a cross-sectional study. Vacunas 2022; 23:S22-5.^,8585. Oliveira BLCA, Campos MAG, Queiroz RCS, Alves MTSSB, Souza BF, Santos AM, et al. Prevalência e fatores associados à hesitação vacinal contra a COVID-19 no Maranhão, Brasil. Rev Saúde Pública 2021; 55:12.. Then, inserting religious leaders in vaccination campaigns can be beneficial for vaccine adherence ⁸⁶86. Domek GJ, O’Leary ST, Bull S, Bronsert M, Contreras-Roldan IL, Bolaños Ventura GA, et al. Measuring vaccine hesitancy: field testing the WHO SAGE Working Group on Vaccine Hesitancy survey tool in Guatemala. Vaccine 2018; 36:5273-81.^,8787. Gerede R, Machekanyanga Z, Ndiaye S, Chindedza K, Chigodo C, Shibeshi ME, et al. How to increase vaccination acceptance among Apostolic communities: quantitative results from an assessment in three provinces in Zimbabwe. J Relig Health 2017; 56:1692-700.^,8888. Machekanyanga Z, Ndiaye S, Gerede R, Chindedza K, Chigodo C, Shibeshi ME, et al. Qualitative assessment of vaccination hesitancy among members of the Apostolic church of Zimbabwe: a case study. J Relig Health 2017; 56:1683-91..

Another important aspect in this review is the relationship between the studies and the publications of the WHO SAGE working group. Although WHO SAGE has establishes a definition for vaccine hesitancy, this term has been used in different ways in studies and this lack of conceptual clarity can lead to mistaken interpretations and generate confusion among researchers ⁸⁹89. Bussink-Voorend D, Hautvast JLA, Vandeberg L, Visser O, Hulscher MEJL. A systematic literature review to clarify the concept of vaccine hesitancy. Nat Hum Behav 2022; 6:1634-48.^,9090. Bedford H, Attwell K, Danchin M, Marshall H, Corben P, Leask J. Vaccine hesitancy, refusal and access barriers: the need for clarity in terminology. Vaccine 2018; 36:6556-8.^,9191. Dubé E, Ward JK, Verger P, MacDonald NE. Vaccine hesitancy, acceptance, and anti-vaccination: trends and future prospects for public health. Annu Rev Public Health 2021; 42:175-91.. Of note, the concept originally established for “vaccine hesitancy” has already been altered because of the resulting criticisms and reflections. In 2022, the BeSD working group proposed a new definition for vaccine hesitancy as a “motivational state of being conflicted about, or opposed to, getting vaccinated; includes intentions and willingness” ¹⁰10. World Health Organization. Behavioural and social drivers of vaccination: tools and practical guidance for achieving high uptake. Geneva: World Health Organization; 2022. (p. VII).

Vaccine hesitancy can be used to explain concerns and questions about vaccination, the interval between the continuum between accepting and refusing all vaccines, used as a synonym for non-vaccination ⁸⁹89. Bussink-Voorend D, Hautvast JLA, Vandeberg L, Visser O, Hulscher MEJL. A systematic literature review to clarify the concept of vaccine hesitancy. Nat Hum Behav 2022; 6:1634-48.^,9090. Bedford H, Attwell K, Danchin M, Marshall H, Corben P, Leask J. Vaccine hesitancy, refusal and access barriers: the need for clarity in terminology. Vaccine 2018; 36:6556-8.. On the other hand, because it has very comprehensive definitions and is used in studies with different population profiles, contexts, and explanatory factors, vaccine hesitancy can be considered a comprehensive category, and not an empirical concept ⁹²92. Peretti-Watel P, Larson HJ, Ward JK, Schulz WS, Verger P. Vaccine hesitancy: clarifying a theoretical framework for an ambiguous notion. PLoS Curr 2015; 7:ecurrents.outbreaks.6844c80ff9f5b273f34c91f71b7fc289..

Regarding the use of method designs and research instruments based on WHO SAGE publications, only 6 of all 94 studies in this review used these instruments. However, it should be noted that this review was conducted in January 2022, i.e., before the release of BeSD working group document. Even so, considering that other tools issued by the WHO were well established and validated, such as the Matrix of Determinants and the 5C scale, it is interesting that few studies have used them.

In the perspective of the Global Health, initiatives for the formulation of “global” policies and documents, based on the perspective and expertise of Global North countries and constantly defended by the WHO to be replicated in different contexts, have been criticized ¹⁸18. Montenegro CR, Bernales M, Gonzalez-Aguero M. Teaching global health from the south: challenges and proposals. Crit Public Health 2020; 30:127-9.^,9393. Adams V, Burke NJ, Whitmarsh I. Slow research: thoughts for a movement in global health. Med Anthropol 2014; 33:179-97.. Local specificities, for not allowing large-scale comparisons and implementation of policy and models and for requiring unique and adaptable responses, tend to be ignored ⁹³93. Adams V, Burke NJ, Whitmarsh I. Slow research: thoughts for a movement in global health. Med Anthropol 2014; 33:179-97.. Top-down “one-size-fits-all” initiatives do not take into account living conditions and characteristics of the communities where they will be applied ⁹⁴94. Ortega F, Behague DP. O que a medicina social latino-americana pode contribuir para os debates globais sobre as políticas da Covid-19: lições do Brasil. Physis (Rio J.) 2020; 30:e300205.. Considering the above, the application of the vaccine hesitancy concept and instruments validated by the WHO may not be adequate to analyze issues of access to vaccines and cost in countries where vaccination is not universal.

Study limitations

The limitations of this scoping review are related to the methodological stages of this type of study. Although a comprehensive search strategy was adopted, some relevant studies may not have been selected, such as technical studies and studies published in French, considering this language is spoken in some African countries. This review did not analyze how each study addressed hesitancy and acceptance in the questions of surveys and scripts of qualitative studies. In addition, the selected studies were not evaluated in terms of evidence quality, as the objective was to map studies on COVID-19 vaccine hesitancy in African and Latin American countries.

Final considerations

The discussion about vaccine hesitancy and, more specifically, COVID-19 vaccine hesitancy, has been the subject of global discussion. The issues presented in this scoping review show that COVID-19 vaccine hesitancy in countries of the Global South is a complex phenomenon.

The use of instruments produced by the Global North can lead to a failure to understand the different social, cultural, and regional aspects involved in COVID-19 vaccine hesitancy, but these aspects are essential for further studies and implementation of health actions ⁹9. Matos CCSA, Gonçalves BA, Couto MT. Vaccine hesitancy in the global south: towards a critical perspective on global health. Glob Public Health 2022; 17:1087-98..

This scoping review showed that vaccine acceptance and hesitancy rates significantly ranged in different locations, which also indicates that particularities of these locations must be considered as different reasons for vaccine hesitancy. Also, most studies selected in this review are quantitative/epidemiological studies, which may also limit the understanding of vaccine hesitancy complexity in regional, local, and cultural aspects of African and Latin American countries. Then, qualitative studies in social sciences allow the analysis of thick description to understand the beliefs and attitudes that involve the phenomenon of COVID-19 vaccine hesitancy ⁷⁰70. Moulin AM. A hipótese vacinal: por uma abordagem crítica e antropológica de um fenômeno histórico. Hist Ciênc Saúde-Manguinhos 2003; 10:499-517.. In this sense, and based on the understanding of the Global South particularities, effective responses should be developed to address each particularity.

Acknowledgments

We thank the Brazilian Coordination for the Improvement of Higher Education Personnel (CAPES) and the extension project titled The COVID-19 Pandemic in Peripheral Territories: Dialogues between Brazil and South Africa conducted by members of the Department of Anthropology at Faculty of Philosophy, Languages and Human Sciences, University of São Paulo (FFLCH/USP) and the Department of Preventive Medicine at Faculty of Medicine, University of São Paulo (FMUSP).

References

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