ABSTRACT

Since March 2020, Brazil has faced the pandemic of the coronavirus disease 2019 (Covid-19), which has severely modified the way in which the population lives and uses health services. As such, face-to-face attendance has dropped dramatically, even for child vaccination, due to measures of social distancing to mitigate the transmission of the virus. Several countries have recorded a substantial drop in vaccination coverage in children, especially of those under two years of age. In Brazil, administrative data indicate the impact of the covid-19 pandemic on this downward trend, which was already an important challenge of the National Immunization Program in recent years. Many children will be susceptible to immunopreventable diseases, which reinforces the need to assess the vaccine status of schoolchildren before returning to face-to-face classes.

DESCRIPTORS:
Coronavirus Infections; prevention & control; Vaccine-Preventable Diseases; Immunization Coverage; Immunization Programs

INTRODUCTION

Vaccination (along with other public policies, especially those aimed at expanding sanitation) has made possible to substantially decrease the number of deaths of children under five years of age worldwide¹1. World Health Organization. Global Vaccine Action Plan 2011-2020: review and lessons learned. Geneva: WHO; 2019.. Widespread vaccination allowed the eradication or control of immunopreventable diseases in several regions of the world, including Brazil, due to successful immunization programs¹1. World Health Organization. Global Vaccine Action Plan 2011-2020: review and lessons learned. Geneva: WHO; 2019.^–33. Greenwood B. The contribution of vaccination to global health: past, present and future. Philos Trans R Soc Lond B Biol Sci. 2014;369(1645):20130433. https://doi.org/10.1098/rstb.2013.0433
https://doi.org/10.1098/rstb.2013.0433... .

In Brazil, since the 1990s, vaccine coverage in children under one year of age had rates above 95%, which indicated the high participation of the population in vaccination and the good performance of the National Immunization Program (NIP)⁴4. Domingues CMAS, Teixeira AMS. Coberturas vacinais e doenças imunopreveníveis no Brasil no período 1982-2012: avanços e desafios do Programa Nacional de Imunizações. Epidemiol Serv Saude. 2013;22(1):9-27. https://doi.org/10.5123/S1679-49742013000100002
https://doi.org/10.5123/S1679-4974201300... . The gradual implementation of the Brazilian Unified Health System (SUS) in the late 1980s allowed for a high rate of vaccine coverage through the expansion and decentralization of health services, mainly due to its principle of universal and free access to vaccination⁵5. Paim JS, Travassos CMR, Almeida CM, Bahia L, Macinko J. The Brazilian health system: history, advances, and challenges. Lancet. 2011;377(9779):1778-97. https://doi.org/10.1016/S0140-6736(11)60054-8
https://doi.org/10.1016/S0140-6736(11)60... ^–66. Waldman EA, Sato APS, Fortaleza CMCB. Doenças infecciosas no Brasil: das endemias rurais às modernas pandemias. In: Monteiro CA, Levy RB, organizadores. Velhos e novos males da saúde no Brasil: de Geisel a Dilma. São Paulo: Hucitec; 2015. v.1; p.234-311..

Throughout its history, the NIP faced several challenges. In the 1980s, the first national surveys of vaccination coverage showed worse coverage in poorer segments of the population; this difference disappeared in the late 1990s, indicating that equity of access to vaccination had been reached in different socioeconomic strata of Brazil²2. Barreto ML. Teixeira GM, Bastos FI, Ximenes RAA, Barata RB, Rodrigues LC. Successes and failures in the control of infectious diseases in Brazil: social and environmental context, policies, interventions, and research needs. Lancet Ser Health in Brazil. 2011;377(9780):1877-89. https://doi.org/10.1016/S0140-6736(11)60202-X
https://doi.org/10.1016/S0140-6736(11)60... ^,77. Antunes JLF, Waldman EA, Borrell C, Paiva TM. Effectiveness of influenza vaccination and its impact on health inequalities. Int J Epidemiol. 2007;36(6):1319-26. https://doi.org/10.1093/ije/dym208
https://doi.org/10.1093/ije/dym208... ^,88. Waldman EA. Mesa-Redonda: Desigualdades sociais e cobertura vacinal: uso de inquéritos domiciliares. Rev Bras Epidemiol. 2008;11 Supl 1:129-32. https://doi.org/10.1590/S1415-790X2008000500013
https://doi.org/10.1590/S1415-790X200800... . However, according to the 2007 national survey, the country now has a lower coverage on both the richer and the extremely poor demographics⁹9. Barata RB, Ribeiro MCSA, Moraes JC, Flannery B; Vaccine Coverage Survey 2007 Group. Socioeconomic inequalities and vaccination coverage: results of an immunisation coverage survey in 27 Brazilian capitals, 2007-2008. J Epidemiol Community Health. 2012;66(10):934-41. https://doi.org/10.1136/jech-2011-200341
https://doi.org/10.1136/jech-2011-200341... . Moreover, from 2016 onwards vaccine coverage rates have declined about 10% to 20%¹⁰10. Sato APS. Qual a importância da hesitação vacinal na queda das coberturas vacinais no Brasil? Rev Saude Publica. 2018;52:96. https://doi.org/10.11606/S1518-8787.2018052001199
https://doi.org/10.11606/S1518-8787.2018... ^,1111. Césare N, Mota TF, Lopes FFL, Lima ACM, Luzardo R, Quintanilha LF, et al. Longitudinal profiling of the vaccination coverage in Brazil reveals a recent change in the patterns hallmarked by differential reduction across regions. Int J Infect Dis. 2020;98:275-80. https://doi.org/10.1016/j.ijid.2020.06.092
https://doi.org/10.1016/j.ijid.2020.06.0... , due to factors not yet understood. The measles epidemic that hit several states in 2018 and 2019 is an immediate consequence of the decrease in vaccine coverage¹²12. Pacheco FC, França GVA, Elidio GA, Domingues CMAS, Oliveira C, Guilhem DB. Trends and spatial distribution of MMR vaccine coverage in Brazil during 2007-2017. Vaccine. 2019;37(20):2651-5. https://doi.org/10.1016/j.vaccine.2019.04.019
https://doi.org/10.1016/j.vaccine.2019.0... .

Among the possible explanations for this, we have the decrease in the perception of risk of these diseases and the increased perception of risk of adverse events following immunization (AEFI). This phenomenon was also recorded in other countries, due to the success of immunization programs when disease control or elimination is reached, a result of the prolonged maintenance of high vaccination coverage. Thus, success itself has become a great challenge¹³13. Chen RT, Orenstein WA. Epidemiologic methods in immunization programs. Epidemiol Rev. 1996;18(2):99-117. https://doi.org/10.1093/oxfordjournals.epirev.a017931
https://doi.org/10.1093/oxfordjournals.e... .

However, it is accepted that this is not the sole reason: among other factors that influenced the drop in vaccination coverage since 2016, the emergence of vaccine hesitancy is highlighted. This a phenomenon that has gained importance in various parts of the world and is characterized by the delay in accepting or refusal of the vaccine, regardless of its availability and access to health services¹⁰10. Sato APS. Qual a importância da hesitação vacinal na queda das coberturas vacinais no Brasil? Rev Saude Publica. 2018;52:96. https://doi.org/10.11606/S1518-8787.2018052001199
https://doi.org/10.11606/S1518-8787.2018... ^,1414. MacDonald NE; SAGE Working Group on Vaccine Hesitancy. Vaccine hesitancy: definition, scope and determinants. Vaccine. 2015;33(34):4161-4. https://doi.org/10.1016/j.vaccine.2015.04.036
https://doi.org/10.1016/j.vaccine.2015.0... ^–1616. Brown AL, Sperandio M, Turssi CP, Leite RMA, Berton VF, Succi RM, et al. Vaccine confidence and hesitancy in Brazil. Cad Saude Publica. 2018;34(9):e00011618. https://doi.org/10.1590/0102-311X00011618
https://doi.org/10.1590/0102-311X0001161... .

The political and economic crisis, the decrease in government support for the SUS¹⁷17. Souza LEPF, Paim JS, Teixeira CF, Bahia L, Guimarães R, Almeida-Filho N, et al. Os desafios atuais da luta pelo direito universal à saúde no Brasil. Cienc Saude Coletiva. 2019;24(8):2783-92. https://doi.org/10.1590/1413-81232018248.34462018
https://doi.org/10.1590/1413-81232018248... and the dissemination by social networks of distorted information about vaccines are also worthy of mention, all of which possibly contributed to the sharp drop in vaccine coverage in recent years¹⁸18. Gostin LO, Hodge JG Jr, Bloom BR, El-Mohandes A, Fielding J, Hotez P, et al. The public health crisis of underimmunisation: a global plan of action. Lancet Infect Dis. 2020;20(1):e11-e16. https://doi.org/10.1016/S1473-3099(19)30558-4
https://doi.org/10.1016/S1473-3099(19)30... ^–2020. Rochel de Camargo Jr K. Here we go again: the reemergence of anti-vaccine activism on the Internet. Cad Saude Publica. 2020;36 Supl 2:e00037620. https://doi.org/10.1590/0102-311x00037620
https://doi.org/10.1590/0102-311x0003762... .

THE GLOBAL IMPACT OF PANDEMIC ON CHILD VACCINATION

In 2020, due to the pandemic of coronavirus disease 2019 (covid-19), face-to-face attendance in health services dropped dramatically in many countries; this included child vaccination, given the measures of social distancing to mitigate viral transmission²¹21. Abbas K, Procter SR, Zandvoort K, Clark A, Funk S, Mengistu S, et al. Routine childhood immunisation during the COVID-19 pandemic in Africa: a benefit-risk analysis of health benefits versus excess risk of SARS-CoV-2 infection. Lancet Glob Health. 2020;S2214-109X(20)30308-9. https://doi.org/10.1016/S2214-109X(20)30308-9
https://doi.org/10.1016/S2214-109X(20)30... ^–2727. Suwantika AA, Boersma C, Postma MJ. The potential impact of COVID-19 pandemic on the immunization performance in Indonesia. Expert Rev Vaccines. 2020;19(8):687-90. https://doi.org/10.1080/14760584.2020.1800461
https://doi.org/10.1080/14760584.2020.18... .

Efforts to contain the pandemic, which involve distant medicine practices and the use of other technologies in order to continue health care at home, have affected vaccination actions, which require travels to the healthcare unit²²22. Bramer CA, Kimmins LM, Swanson R, Kuo J, Vranesich P, Jacques-Carrol LA, Shen AK. Decline in child vaccination coverage during the COVID-19 Pandemic - Michigan Care Improvement Registry, May 2016-May 2020. MMWR Morb Mortal Wkly Rep. 2020;69(20):630-1. https://doi.org/10.15585/mmwr.mm6920e1
https://doi.org/10.15585/mmwr.mm6920e1... . Parental concern in exposing children to Sars-CoV-2 when taking them to health services for vaccination also contributed to the decline in vaccination coverage²²22. Bramer CA, Kimmins LM, Swanson R, Kuo J, Vranesich P, Jacques-Carrol LA, Shen AK. Decline in child vaccination coverage during the COVID-19 Pandemic - Michigan Care Improvement Registry, May 2016-May 2020. MMWR Morb Mortal Wkly Rep. 2020;69(20):630-1. https://doi.org/10.15585/mmwr.mm6920e1
https://doi.org/10.15585/mmwr.mm6920e1... ^,2424. McDonald HI, Tessier E, White JM, Woodruff M, Knowles C, Bates C, et al. Early impact of the coronavirus disease (COVID-19) pandemic and physical distancing measures on routine childhood vaccinations in England, January to April 2020. Euro Surveill. 2020;25(19):2000848. https://doi.org/10.2807/1560-7917.ES.2020.25.19.2000848
https://doi.org/10.2807/1560-7917.ES.202... ^–2626. Saxena S, Skirrow H, Bedford H. Routine vaccination during covid-19 pandemic response. BMJ. 2020;369:m2392. https://doi.org/10.1136/bmj.m2392
https://doi.org/10.1136/bmj.m2392... ^,2828. Hirabayashi K. The impact of COVID-19 on the routine vaccinations: refletions during World Immunization Week 2020. Bangkok (THA): UNICEF-East Asia and Pacific; 2020 [cited 2020 Sep 10]. Available from: https://www.unicef.org/eap/stories/impact-covid-19-routine-vaccinations
https://www.unicef.org/eap/stories/impac... . A risk-benefit study in African countries showed that avoidable deaths from routine vaccination outweigh the excess risk of death from covid-19 associated with attendance at the healthcare unit, evidencing the need for increasing vaccination coverage at this time²¹21. Abbas K, Procter SR, Zandvoort K, Clark A, Funk S, Mengistu S, et al. Routine childhood immunisation during the COVID-19 pandemic in Africa: a benefit-risk analysis of health benefits versus excess risk of SARS-CoV-2 infection. Lancet Glob Health. 2020;S2214-109X(20)30308-9. https://doi.org/10.1016/S2214-109X(20)30308-9
https://doi.org/10.1016/S2214-109X(20)30... .

Child vaccination coverage has declined sharply during the pandemic in several regions of the world²⁶26. Saxena S, Skirrow H, Bedford H. Routine vaccination during covid-19 pandemic response. BMJ. 2020;369:m2392. https://doi.org/10.1136/bmj.m2392
https://doi.org/10.1136/bmj.m2392... ^,2828. Hirabayashi K. The impact of COVID-19 on the routine vaccinations: refletions during World Immunization Week 2020. Bangkok (THA): UNICEF-East Asia and Pacific; 2020 [cited 2020 Sep 10]. Available from: https://www.unicef.org/eap/stories/impact-covid-19-routine-vaccinations
https://www.unicef.org/eap/stories/impac... . In the USA, a considerable decline in the vaccine coverage of children was found, starting in the week after the national emergency scenario was declared (March 13, 2020). Higher rates were found among children under two years of age²⁵25. Santoli JM, Lindley MC, DeSilva MB, Kharbanda EO, Daley MF, Galloway L, Gee J, et al. Effects of the COVID-19 pandemic on routine eediatric vaccine ordering and administration - United States, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(19):591-3. https://doi.org/10.15585/mmwr.mm6919e2
https://doi.org/10.15585/mmwr.mm6919e2... . In England, three weeks after the introduction of social distancing (March 20, 2020), there was a 19.8% drop in doses of the measles-mumps-rubella vaccine, compared to the same period in 2019²⁴24. McDonald HI, Tessier E, White JM, Woodruff M, Knowles C, Bates C, et al. Early impact of the coronavirus disease (COVID-19) pandemic and physical distancing measures on routine childhood vaccinations in England, January to April 2020. Euro Surveill. 2020;25(19):2000848. https://doi.org/10.2807/1560-7917.ES.2020.25.19.2000848
https://doi.org/10.2807/1560-7917.ES.202... . In Michigan (USA), completeness of the vaccination schedule for five-year olds dropped from 67.0% to 49.7% in May 2020. At 16 months, it was found that measles vaccine coverage decreased from 76.1% to 70.9%²²22. Bramer CA, Kimmins LM, Swanson R, Kuo J, Vranesich P, Jacques-Carrol LA, Shen AK. Decline in child vaccination coverage during the COVID-19 Pandemic - Michigan Care Improvement Registry, May 2016-May 2020. MMWR Morb Mortal Wkly Rep. 2020;69(20):630-1. https://doi.org/10.15585/mmwr.mm6920e1
https://doi.org/10.15585/mmwr.mm6920e1... . In Indonesia, where immunization occurs in schools, a significant drop in coverage of the basic vaccination schedule was predicted after the closure of schools in March 2020²⁷27. Suwantika AA, Boersma C, Postma MJ. The potential impact of COVID-19 pandemic on the immunization performance in Indonesia. Expert Rev Vaccines. 2020;19(8):687-90. https://doi.org/10.1080/14760584.2020.1800461
https://doi.org/10.1080/14760584.2020.18... . Moreover, it is known that this impact will be even more important in families with unfavorable socioeconomic conditions²⁶26. Saxena S, Skirrow H, Bedford H. Routine vaccination during covid-19 pandemic response. BMJ. 2020;369:m2392. https://doi.org/10.1136/bmj.m2392
https://doi.org/10.1136/bmj.m2392... .

The World Health Organization (WHO) estimates that at least 80 million children will be susceptible to immunopreventable diseases such as measles, diphtheria and polio because of the decrease in vaccination coverage during the covid-19 pandemic²⁹29. World Health Organization. At least 80 million children under one at risk of diseases such as diphtheria, measles and polio as COVID-19 disrupts routine vaccination efforts, warn Gavi, WHO and UNICEF [news release]. Geneva: WHO, May 22, 2020 [cited 2020 Sep 10]. Available from: https://www.who.int/news-room/detail/22-05-2020-at-least-80-million-children-under-one-at-risk-of-diseases-such-as-diphtheria-measles-and-polio-as-covid-19-disrupts-routine-vaccination-efforts-warn-gavi-who-and-unicef
https://www.who.int/news-room/detail/22-... . It is worth remembering that outbreaks of measles were attributed to the interruption of vaccination services during the 2013–2016 Ebola epidemic in West Africa, causing a second public health crisis³⁰30. Takahashi S, Metcalf CJE, Ferrari MJ, Moss WJ, Truelove AS, Tatem AJ, et al. Reduced vaccination and the risk of measles and other childhood infections post-Ebola. Science. 2015;347(6227):1240-2. https://doi.org/10.1126/science.aaa3438
https://doi.org/10.1126/science.aaa3438... ^–3131. Elston JWT, Cartwright C, Ndumbi P, Wright J. The health impact of the 2014-15 Ebola outbreak. Public Health. 2017;143:60-70. https://doi.org/10.1016/j.puhe.2016.10.020
https://doi.org/10.1016/j.puhe.2016.10.0... .

The pandemic of the new coronavirus has challenged health systems around the world in providing essential services, including immunization programs, as routine vaccination and mass vaccination campaigns could contribute to the spread of covid-19³²32. Nelson R. COVID-19 disrupts vaccine delivery. Lancet Infect Dis. 2020;20(5):546. https://doi.org/10.1016/S1473-3099(20)30304-2
https://doi.org/10.1016/S1473-3099(20)30... .

On March 26, 2020, WHO and the Pan American Health Organization published recommendations on vaccination during the covid-19 pandemic. The measures considered three scenarios of availability of health services and included the temporary suspension of mass vaccination campaigns during this period. It was recommended that routine vaccination be maintained in places where essential health services had operational capacity of human resources and supply of preserved vaccines, respecting social distancing and other measures to control transmission of Sars-CoV-2³³33. World Health Organization. Guiding principles for immunization activities during the COVID-19 pandemic. Geneva: WHO; 2020 [cited 2020 Sep 10]. Available from: https://apps.who.int/iris/bitstream/handle/10665/331590/WHO-2019-nCoV-immunization_services-2020.1-eng.pdf
https://apps.who.int/iris/bitstream/hand... ^,3434. Pan American Health Organization. The immunization program in the context of the COVID-19 pandemic – March 2020. Washington, DC; PAHO; 2020 [cited 2020 Sep 10]. Available from: https://www.paho.org/en/documents/immunization-program-context-covid-19-pandemic-march-2020
https://www.paho.org/en/documents/immuni... .

In Brazil there was the recommendation of suspending routine immunization during the first 15 days of the influenza vaccination campaign, as this was a period in which older adults and health professionals were supposed to be vaccinated; although this was valid as a safety measure for the older population, it has generated concern among Brazilian medical societies³⁵35. Sociedade Brasileira de Pediatria; Sociedade Brasileira de Imunizações. Calendário vacinal da criança e a pandemia pelo coronavírus. Rio de Janeiro: SBP; 2020 [cited 2020 Sep 10]. Available from: https://www.sbp.com.br/fileadmin/user_upload/nt-sbpsbim-calendariodacrianca-pandemiacovid-200324.pdf
https://www.sbp.com.br/fileadmin/user_up... .

The WHO recognizes this fragility and recommends efforts to ensure high vaccination coverage, seeking herd immunization for preventable diseases, in such way that vaccination programs should adopt innovative measures³⁶36. Pan American Health Organization. Vaccination of newborns in the context of the COVID-19 pandemic,19 May 2020. Washington DC: PAHO; 2020 [cited 2020 Sep 10]. Available from: https://iris.paho.org/handle/10665.2/52226
https://iris.paho.org/handle/10665.2/522... ^,3737. World Health Organization Regional Office for Europe. Guidance on routine immunization services during COVID-19 pandemic in the WHO European Region. Copenhagen (DNK); 2020 [cited 2020 Sep 10]. Available from: http://www.euro.who.int/__data/assets/pdf_file/0004/433813/Guidance-routine-immunization-services-COVID-19-pandemic.pdf?ua=1
http://www.euro.who.int/__data/assets/pd... . Vaccination strategies in vehicles, at home or in specific rooms and well-separated from the locations of other clinical visits could be used, as well as the identification of absentees and recruitment for vaccination with the aid of electronic immunization registries (EIR)²²22. Bramer CA, Kimmins LM, Swanson R, Kuo J, Vranesich P, Jacques-Carrol LA, Shen AK. Decline in child vaccination coverage during the COVID-19 Pandemic - Michigan Care Improvement Registry, May 2016-May 2020. MMWR Morb Mortal Wkly Rep. 2020;69(20):630-1. https://doi.org/10.15585/mmwr.mm6920e1
https://doi.org/10.15585/mmwr.mm6920e1... ^,2424. McDonald HI, Tessier E, White JM, Woodruff M, Knowles C, Bates C, et al. Early impact of the coronavirus disease (COVID-19) pandemic and physical distancing measures on routine childhood vaccinations in England, January to April 2020. Euro Surveill. 2020;25(19):2000848. https://doi.org/10.2807/1560-7917.ES.2020.25.19.2000848
https://doi.org/10.2807/1560-7917.ES.202... ^–2626. Saxena S, Skirrow H, Bedford H. Routine vaccination during covid-19 pandemic response. BMJ. 2020;369:m2392. https://doi.org/10.1136/bmj.m2392
https://doi.org/10.1136/bmj.m2392... ^,2828. Hirabayashi K. The impact of COVID-19 on the routine vaccinations: refletions during World Immunization Week 2020. Bangkok (THA): UNICEF-East Asia and Pacific; 2020 [cited 2020 Sep 10]. Available from: https://www.unicef.org/eap/stories/impact-covid-19-routine-vaccinations
https://www.unicef.org/eap/stories/impac... .

EIR allow greater efficiency of health services, because, in addition to providing the evaluation of vaccination coverage, they also help in routine practice and enable the convocation of absentees, thus increasing the scope of immunization³⁸38. Sato APS. National Immunization Program: computerized system as a tool for new challenges. Rev Saude Publica. 2015;49:39. https://doi.org/10.1590/S0034-8910.2015049005925
https://doi.org/10.1590/S0034-8910.20150... ^,3939. Cutts FT, Claquin P, Danovaro-Holliday MC, Rhoda DA. Monitoring vaccination coverage: defining the role of surveys. Vaccine. 2016;34(35):4103-9. https://doi.org/10.1016/j.vaccine.2016.06.053
https://doi.org/10.1016/j.vaccine.2016.0... . In addition, they are important sources of information, which can be applied in the evaluation of performance indicators and in the development of epidemiological research³⁸38. Sato APS. National Immunization Program: computerized system as a tool for new challenges. Rev Saude Publica. 2015;49:39. https://doi.org/10.1590/S0034-8910.2015049005925
https://doi.org/10.1590/S0034-8910.20150... ^,4040. Luhm KR, Waldman EA. Sistemas informatizados de registro de imunização: uma revisão com enfoque na saúde infantil. Epidemiol Serv Saude. 2009;18(1):65-78. https://doi.org/10.5123/S1679-49742009000100007
https://doi.org/10.5123/S1679-4974200900... . In 2020, researchers from countries such as the USA and the United Kingdom evaluated in real time the decline in vaccination coverage and the number of doses applied during the covid-19 pandemic through EIR. With this quick identification, it is possible to quickly adopt strategies in the face of this challenge²²22. Bramer CA, Kimmins LM, Swanson R, Kuo J, Vranesich P, Jacques-Carrol LA, Shen AK. Decline in child vaccination coverage during the COVID-19 Pandemic - Michigan Care Improvement Registry, May 2016-May 2020. MMWR Morb Mortal Wkly Rep. 2020;69(20):630-1. https://doi.org/10.15585/mmwr.mm6920e1
https://doi.org/10.15585/mmwr.mm6920e1... ^,2424. McDonald HI, Tessier E, White JM, Woodruff M, Knowles C, Bates C, et al. Early impact of the coronavirus disease (COVID-19) pandemic and physical distancing measures on routine childhood vaccinations in England, January to April 2020. Euro Surveill. 2020;25(19):2000848. https://doi.org/10.2807/1560-7917.ES.2020.25.19.2000848
https://doi.org/10.2807/1560-7917.ES.202... ^,2525. Santoli JM, Lindley MC, DeSilva MB, Kharbanda EO, Daley MF, Galloway L, Gee J, et al. Effects of the COVID-19 pandemic on routine eediatric vaccine ordering and administration - United States, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(19):591-3. https://doi.org/10.15585/mmwr.mm6919e2
https://doi.org/10.15585/mmwr.mm6919e2... .

With the emergence of many radical groups worldwide that deny the importance of the pandemic and its associated mitigation measures, vaccine hesitancy might acquire more strength, especially considering the availability of vaccines for covid-19 in the near future that will have an important role in dealing with this disease⁴¹41. McAteer J, Yildirim I, Chahroudi A. The VACCINES Act: deciphering vaccine hesitancy in the time of COVID-19. Clin Infect Dis. 2020;71(15):703-5. https://doi.org/10.1093/cid/ciaa433
https://doi.org/10.1093/cid/ciaa433... .

CHALLENGES OF RETURNING TO SCHOOLS

The safe resumption of day care centers and schools should be a national priority. Children have lost fundamental benefits of social, educational and developmental nature. For many parents, it will not be possible to return to work if these institutions remain closed, thus exacerbating social inequities. Several individual practices (use of masks, hygiene, social distancing, temperature measurement etc) as well as environmental ones (maximum capacity and layout of classrooms, cleaning etc) will be necessary to prevent the transmission of Sars-CoV-2 between schoolchildren and staff, including in transportation to schools⁴²42. Barnes M, Sax PE. Challenges of “return to work” in an ongoing pandemic. N Engl J Med. 2020;383(8):779-86. https://doi.org/10.1056/NEJMsr2019953
https://doi.org/10.1056/NEJMsr2019953... ^,4343. Levinson M, Cevik M, Lipsitch M. Reopening primary schools during the pandemic. N Engl J Med. 2020;383(10):981-5. https://doi.org/10.1056/NEJMms2024920
https://doi.org/10.1056/NEJMms2024920... .

However, in addition to care for covid-19⁴⁴44. Betz CL. COVID-19 and school return: the need and necessity. J Pediatr Nurs. 2020;54:A7-A9. https://doi.org/10.1016/j.pedn.2020.07.015
https://doi.org/10.1016/j.pedn.2020.07.0... , the American Academy of Pediatrics recommended that schools, health services, and local health authorities promote child vaccination well before the beginning of the school year. It is important that children receive vaccines at the recommended age and be updated in case of vaccine delay due to the pandemic⁴⁵45. American Academy of Pediatrics. COVID-19 planning considerations: guidance for school re-entry. Itasca, IL: AAP; 2020 [cited 2020 Sep 10]. Available from: https://services.aap.org/en/pages/2019-novel-coronavirus-covid-19-infections/clinical-guidance/covid-19-planning-considerations-return-to-in-person-education-in-schools/
https://services.aap.org/en/pages/2019-n... . This recommendation should be considered in other countries, including Brazil.

In Brazil, the pandemic was an additional challenge for the return to schools due to the abovementioned immunopreventable diseases, as we recently faced a consistent drop in vaccination coverage and a wide epidemic of measles that reached several states and amounted for thousands of cases. This situation has worsened in 2020, which until August had registered more than 7,000 confirmed cases of measles⁴⁶46. Ministério da Saúde, Secretaria de Vigilância em Saúde. Vigilância Epidemiológica do sarampo no Brasil – 2020 Semanas Epidemiológicas 1 a 32. Bol Epidemiol. 2020 [cited 2020 Sep 10];51(34):1-10. Available from: https://antigo.saude.gov.br/images/pdf/2020/August/31/Boletim-epidemiologico-SVS-34.pdf
https://antigo.saude.gov.br/images/pdf/2... .

According to data from the NIP Information System (IS-NIP), when comparing the number of first doses of the pentavalent vaccine applied in March 2020 with March 2019, we found a decrease of 27% (Figure)¹⁰10. Sato APS. Qual a importância da hesitação vacinal na queda das coberturas vacinais no Brasil? Rev Saude Publica. 2018;52:96. https://doi.org/10.11606/S1518-8787.2018052001199
https://doi.org/10.11606/S1518-8787.2018... ^–1111. Césare N, Mota TF, Lopes FFL, Lima ACM, Luzardo R, Quintanilha LF, et al. Longitudinal profiling of the vaccination coverage in Brazil reveals a recent change in the patterns hallmarked by differential reduction across regions. Int J Infect Dis. 2020;98:275-80. https://doi.org/10.1016/j.ijid.2020.06.092
https://doi.org/10.1016/j.ijid.2020.06.0... . These data indicate that the return to classes may increase the risk not only of the expansion of measles epidemics throughout the country, but also of the reemergence of other already controlled diseases, such as diphtheria and the whooping cough. Studies show that outbreaks of diphtheria occur when vaccination coverage drops due to migration and/or political instability, emphasizing that it is a disease of relevant lethality⁴⁷47. Truelove SA, Keegan LT, Moss WJ, Chaisson LH, Macher E, Azman AS, et al. Clinical and epidemiological aspects of diphtheria: a systematic review and pooled analysis. Clin Infect Dis. 2020;71(1):89-97. https://doi.org/10.1093/cid/ciz808
https://doi.org/10.1093/cid/ciz808... ^–4949. Vitek CR, Wharton M. Diphtheria in the former Soviet Union: reemergence of a pandemic disease. Emerg Infect Dis. 1998;4(4):539-50. https://doi.org/10.3201/eid0404.980404
https://doi.org/10.3201/eid0404.980404... .

Thus, it is evident that, before the progressive return of face-to-face school activities, intensive actions to assess the vaccine situation of this population will be necessary in order to recover sufficient vaccination coverage to prevent or reduce the spread of immunopreventable diseases⁴⁵45. American Academy of Pediatrics. COVID-19 planning considerations: guidance for school re-entry. Itasca, IL: AAP; 2020 [cited 2020 Sep 10]. Available from: https://services.aap.org/en/pages/2019-novel-coronavirus-covid-19-infections/clinical-guidance/covid-19-planning-considerations-return-to-in-person-education-in-schools/
https://services.aap.org/en/pages/2019-n... . Innovative instruments, such as EIR, can be useful for real-time assessment of vaccination coverage, as well as to warn about immunization and rescue individuals with vaccine delay²²22. Bramer CA, Kimmins LM, Swanson R, Kuo J, Vranesich P, Jacques-Carrol LA, Shen AK. Decline in child vaccination coverage during the COVID-19 Pandemic - Michigan Care Improvement Registry, May 2016-May 2020. MMWR Morb Mortal Wkly Rep. 2020;69(20):630-1. https://doi.org/10.15585/mmwr.mm6920e1
https://doi.org/10.15585/mmwr.mm6920e1... ^,2424. McDonald HI, Tessier E, White JM, Woodruff M, Knowles C, Bates C, et al. Early impact of the coronavirus disease (COVID-19) pandemic and physical distancing measures on routine childhood vaccinations in England, January to April 2020. Euro Surveill. 2020;25(19):2000848. https://doi.org/10.2807/1560-7917.ES.2020.25.19.2000848
https://doi.org/10.2807/1560-7917.ES.202... ^,2525. Santoli JM, Lindley MC, DeSilva MB, Kharbanda EO, Daley MF, Galloway L, Gee J, et al. Effects of the COVID-19 pandemic on routine eediatric vaccine ordering and administration - United States, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(19):591-3. https://doi.org/10.15585/mmwr.mm6919e2
https://doi.org/10.15585/mmwr.mm6919e2... ^,3838. Sato APS. National Immunization Program: computerized system as a tool for new challenges. Rev Saude Publica. 2015;49:39. https://doi.org/10.1590/S0034-8910.2015049005925
https://doi.org/10.1590/S0034-8910.20150... ^–4040. Luhm KR, Waldman EA. Sistemas informatizados de registro de imunização: uma revisão com enfoque na saúde infantil. Epidemiol Serv Saude. 2009;18(1):65-78. https://doi.org/10.5123/S1679-49742009000100007
https://doi.org/10.5123/S1679-4974200900... .

FINAL REMARKS

To date, there are no studies on the impact of covid-19 on the decline in vaccine coverage. Delays in child vaccination (a demographic that should have been immunized in the most intense moment of social distancing) are also yet to be studied, even in other countries. Moreover, despite the universal access to child vaccination achieved by the NIP in the last decade, this impact will probably be greater in children from families with unfavorable socioeconomic conditions, due to less access to health services and information.

When social distancing measures are loosened, many children will be susceptible to preventable diseases, and there will be a need to assess the vaccine situation of schoolchildren before returning to school²²22. Bramer CA, Kimmins LM, Swanson R, Kuo J, Vranesich P, Jacques-Carrol LA, Shen AK. Decline in child vaccination coverage during the COVID-19 Pandemic - Michigan Care Improvement Registry, May 2016-May 2020. MMWR Morb Mortal Wkly Rep. 2020;69(20):630-1. https://doi.org/10.15585/mmwr.mm6920e1
https://doi.org/10.15585/mmwr.mm6920e1... ^,2424. McDonald HI, Tessier E, White JM, Woodruff M, Knowles C, Bates C, et al. Early impact of the coronavirus disease (COVID-19) pandemic and physical distancing measures on routine childhood vaccinations in England, January to April 2020. Euro Surveill. 2020;25(19):2000848. https://doi.org/10.2807/1560-7917.ES.2020.25.19.2000848
https://doi.org/10.2807/1560-7917.ES.202... ^–2626. Saxena S, Skirrow H, Bedford H. Routine vaccination during covid-19 pandemic response. BMJ. 2020;369:m2392. https://doi.org/10.1136/bmj.m2392
https://doi.org/10.1136/bmj.m2392... ^,2828. Hirabayashi K. The impact of COVID-19 on the routine vaccinations: refletions during World Immunization Week 2020. Bangkok (THA): UNICEF-East Asia and Pacific; 2020 [cited 2020 Sep 10]. Available from: https://www.unicef.org/eap/stories/impact-covid-19-routine-vaccinations
https://www.unicef.org/eap/stories/impac... ^,4545. American Academy of Pediatrics. COVID-19 planning considerations: guidance for school re-entry. Itasca, IL: AAP; 2020 [cited 2020 Sep 10]. Available from: https://services.aap.org/en/pages/2019-novel-coronavirus-covid-19-infections/clinical-guidance/covid-19-planning-considerations-return-to-in-person-education-in-schools/
https://services.aap.org/en/pages/2019-n... .

The covid-19 pandemic recalled the importance of vaccination by showing how fast a disease can spread and cause irreparable harm in societies without this defense. When a safe and effective vaccine for Sars-CoV-2 is available, immunization programs will have an even greater challenge of strengthening and reaching those most vulnerable²⁸28. Hirabayashi K. The impact of COVID-19 on the routine vaccinations: refletions during World Immunization Week 2020. Bangkok (THA): UNICEF-East Asia and Pacific; 2020 [cited 2020 Sep 10]. Available from: https://www.unicef.org/eap/stories/impact-covid-19-routine-vaccinations
https://www.unicef.org/eap/stories/impac... .

REFERENCES

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