✓ verbatim from the press
Starting August 3, children aged 4 will once again receive a second polio vaccine booster dose, reversing a change made eight months ago. The Ministry of Health had eliminated this dose in November 2024, when it replaced the mixed schedule — three injectable doses plus two oral boosters — with an exclusive inactivated vaccine (IPV) schedule with only one booster. Now, according to a technical note from the National Immunization Program released in June 2026, the calendar will include five injectable doses: three at 2, 4, and 6 months, and two boosters at 15 months and 4 years. The change was decided by the Technical Advisory Committee on Immunizations. ✓
Press quotes (3)
"A partir de agosto, todas as crianças de 4 anos vão receber mais uma dose de reforço da vacina contra a poliomielite."
"Três doses aos 2, 4 e 6 meses para conferir proteção básica; Duas doses de reforço aos 15 meses e aos 4 anos de idade, para complementar a prevenção."
"A mudança no esquema de vacinação foi decidida após reunião da Câmara Técnica Assessora em Imunizações e comunicada pelo PNI (Programa Nacional de Imunizações) em uma nota técnica na semana passada. Ela passa a valer a partir de 3 de agosto."
The removal of the second booster dose in 2024 was justified by the rare but real risk of mutation of the attenuated virus in the oral vaccine (bOPV), which could cause the disease itself. According to a Technical Report from the Ministry of Health published in 2024, "by November 4, 2024" the two booster doses with bOPV would be replaced by one IPV dose, "so that the vaccination schedule against the disease will be exclusive with IPV". The new decision maintains the exclusive IPV schedule but restores the second booster dose that had been eliminated. ✓
Press quotes (2)
"O Ministério da Saúde, dando continuidade ao processo de erradicação da poliomielite, substituirá até 4 de novembro de 2024 as duas doses de reforço com vacina oral poliomielite bivalente (VOPb) por uma dose de vacina inativada poliomielite (VIP), de modo que o esquema vacinal contra a doença será exclusivo com VIP."
"como em situações muito raras, o vírus atenuado da vacina oral pode sofrer mutações e provocar a doença, o Ministério da Saúde decidiu utilizar exclusivamente a vacina injetável, suprimindo a segunda dose de reforço."
Isabela Ballalai, director of the Brazilian Society of Immunizations, stated that the booster is necessary because "the protection conferred by the vaccine decreases over time". She added that although polio is controlled in the country, "the global situation has shown localized outbreaks that are concerning and increase the risk of reaching the country. So it is better to maintain the two-booster schedule. This is the World Health Organization standard". ✓
Press quotes (2)
"A diretora da Sociedade Brasileira de Imunizações (SBI), Isabela Ballalai, explica que o reforço é necessário porque a proteção conferida pela vacina cai com o passar do tempo."
"A pólio está controlada entre nós. No entanto, a situação mundial vem apresentando surtos localizados que preocupam e aumentam o risco de chegar ao país. Então é melhor manter o esquema de dois reforços. Este é o padrão da Organização Mundial de Saúde"
Brazil has not recorded polio cases for 37 years and received certification as a polio-free area in 1994. Between 1968 and 1989, the country recorded more than 26,000 infections. All children under 5 years who have not completed the five doses should seek health posts for vaccination updates, according to Ministry of Health guidance reported by Agência Brasil. ✓
Press quotes (3)
"O Brasil não registra casos de poliomielite há 37 anos e em 1994 recebeu o certificado de área livre de circulação do vírus."
"De 1968 a 1989, o Brasil registrou mais de 26 mil infecções por pólio."
"Todas as crianças menores de 5 anos que não tiverem recebido as cinco doses devem ser levadas ao posto de saúde para verificar a necessidade de atualização vacinal."
The change takes effect on August 3, 2026 and was decided by the Technical Advisory Committee on Immunizations
The new schedule consists of five injectable IPV doses: three at 2, 4, and 6 months, and two boosters at 15 months and 4 years
Brazil has not recorded polio cases for 37 years and received polio-free certification in 1994
Covered by only some sources, or where the accounts diverge.
Covered by only some sources (3)
Between 1968 and 1989 Brazil recorded more than 26,000 polio infections
The oral vaccine was discontinued because the attenuated virus can, in rare situations, mutate and cause the disease
Isabela Ballalai states that localized international outbreaks increase the risk of virus arrival in Brazil and justify maintaining two boosters according to WHO standard
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What epidemiological evidence justified restoring the second booster dose only eight months after its removal?
Why it's still unknown: The PNI Technical Note that communicated the change was not located by search tools. The press cites the decision of the Technical Advisory Committee on Immunizations and mentions localized international outbreaks, but does not specify which outbreaks, in which countries, nor presents vaccination coverage data or viral circulation that would substantiate the urgency of the reversal.
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What is the current polio vaccination coverage in the 15-month and 4-year age groups in Brazil?
Why it's still unknown: None of the consulted outlets present data from the National Immunization Program Information System (SI-PNI) on vaccination coverage in the age groups affected by the change. The absence of these numbers prevents assessing whether there is a decline in coverage that would justify restoring the booster dose.
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Is there circulation of vaccine-derived poliovirus (VDPV) or wild poliovirus in the Americas that motivates the change?
Why it's still unknown: The coverage cites "localized outbreaks" worldwide but does not identify specific countries nor indicate whether there are cases in the Americas — a region certified polio-free since 1994. WHO publishes epidemiological bulletins that track poliovirus circulation; no outlet consulted this source.
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What is the legal or regulatory basis for the Ministry of Health to modify the national immunization calendar?
Why it's still unknown: The press does not identify a ministerial ordinance, resolution, or other normative act that formalizes the change. It mentions a PNI "technical note," but technical notes do not have regulatory force — they are guidance. It remains unclear whether a ministerial ordinance will be published in the Official Gazette or if the technical note is the only instrument.
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What is the strongest technical argument against restoring the second booster dose?
Why it's still unknown: None of the consulted outlets present critical voices to the decision — neither from public health specialists nor from state or municipal managers who operationalize vaccination. Coverage is unanimous in reproducing the justification from the Ministry of Health and SBI, without contrasting with divergent technical positions or cost-benefit analysis of the measure.