Brazil's vaccination rates plummet 21.5% post-pandemic, study finds

Declining vaccination rates increase disease transmission risk across Brazil's population, particularly affecting vulnerable elderly and underserved northern regions.
Nearly 30% of Brazilians have fallen outside full vaccination compliance
A Unifesp-backed study reveals the scale of post-pandemic vaccine hesitancy across Brazil's population.

Uma nação que já foi símbolo mundial de vacinação em massa agora enfrenta o lento recuo de sua própria confiança imunológica. Pesquisa encomendada pela Unifesp revela que a adesão vacinal no Brasil caiu 21,5% entre julho de 2023 e março de 2026, com quase um terço da população fora dos padrões de imunização completa. O fim da pandemia, em vez de consolidar o legado sanitário conquistado, parece ter aberto espaço para a dúvida — um fenômeno que atravessa gerações, regiões e classes sociais, e que coloca em xeque décadas de cultura vacinal construída com esforço coletivo.

  • Quase 30% dos brasileiros estão fora do padrão de vacinação completa — e entre eles, quase 10% recusam vacinas de forma categórica.
  • O fim da emergência pandêmica não restaurou a confiança: para muitos, a urgência que movia a vacinação simplesmente desapareceu junto com o vírus.
  • A fratura é geracional e geográfica: idosos acima de 60 anos vacinam mais (78%), enquanto jovens se afastam; o Sudeste registra 77,2% de adesão contra apenas 62,5% no Norte.
  • A vacina contra a dengue expõe a contradição: 70% aprovam, mas só 56,7% pretendem se vacinar imediatamente — o sentimento positivo não se converte em ação.
  • Com 4,8% da população assumindo abertamente postura antivacina, o Brasil enfrenta não apenas hesitância, mas uma resistência ideológica em consolidação.

Três anos após o recuo da pandemia, o Brasil vê seu programa de vacinação perder terreno de forma silenciosa, mas mensurável. Um estudo do Instituto Ideia, encomendado pelo centro de pesquisa Sou Ciência da Unifesp, ouviu 1.500 brasileiros com 16 anos ou mais entre fevereiro e março de 2026. O resultado é inquietante: a adesão vacinal caiu 21,5% em comparação a julho de 2023, e quase 30% da população está fora dos padrões de imunização completa. Desse grupo, 9,9% declaram não se vacinar de forma alguma, 9,2% interromperam a vacinação após a pandemia, e 8,8% simplesmente não responderam.

A idade divide o país em dois comportamentos distintos. Entre os brasileiros com mais de 60 anos, 78% mantêm esquemas vacinais considerados ideais. Entre os mais jovens, o engajamento é significativamente menor. A geografia aprofunda essa desigualdade: o Sudeste registra 77,2% de adesão, enquanto o Norte chega a apenas 62,5% — uma diferença de quase 15 pontos percentuais que reflete disparidades históricas no acesso à saúde.

A vacina contra a dengue ilustra com precisão o paradoxo da hesitância contemporânea. Sete em cada dez entrevistados demonstraram sentimento positivo em relação ao imunizante, mas apenas 56,7% afirmaram intenção de se vacinar imediatamente. Os demais se distribuem entre indiferença, incerteza e resistência ativa — com 4,8% se identificando abertamente como antivacina. Entre os idosos, 62% planejam receber a vacina contra a dengue sem demora; entre os jovens, esse número cai para 46%.

O que os dados sugerem é que o fim da pandemia não curou a desconfiança — apenas a deixou emergir. A urgência que mobilizou milhões durante a crise sanitária se dissipou, e no espaço que ficou, a dúvida encontrou lugar para crescer. As fraturas regionais e geracionais apontam para dois problemas que se alimentam mutuamente: acesso desigual e confiança desigual. A questão que fica é se esse recuo representa uma acomodação passageira ou o início de uma erosão mais profunda na saúde pública brasileira.

Three years after the pandemic receded, Brazil's vaccination program is losing ground. A study conducted by the Ideia Institute on behalf of Unifesp's Sou Ciência research center found that vaccination uptake has fallen 21.5 percent when comparing July 2023 to March 2026. The decline marks a troubling reversal in a country that once prided itself on one of the world's most robust immunization campaigns.

The research, carried out between February and March 2026, surveyed 1,500 Brazilians aged 16 and older by telephone. The sample was deliberately diverse—stratified by gender, income, age, education, social class, region, race, and religion—and carries a margin of error of 2.5 percentage points. What emerged from the data was stark: nearly 30 percent of the Brazilian population has fallen outside the standard for full vaccination compliance. Within that group, 9.9 percent say they do not vaccinate at all, 9.2 percent stopped getting vaccinated after the pandemic ended, and 8.8 percent simply did not answer the question.

The picture becomes more complex when age is factored in. Brazilians over 60 are pursuing vaccines at significantly higher rates than younger people. Seventy-eight percent of those aged 60 and above reported maintaining vaccination schedules considered ideal. The inverse holds true for younger cohorts, who show markedly lower engagement with immunization programs. Geography matters too. The Southeast region reports 77.2 percent adherence to vaccination standards, while the North lags at 62.5 percent—a gap of nearly 15 percentage points that reflects deeper disparities in healthcare access and infrastructure.

The dengue vaccine presents a particular case study in vaccine hesitancy. Seventy percent of those surveyed expressed positive sentiment toward the dengue immunization. Yet only 56.7 percent said they intended to get vaccinated immediately. Another 13.7 percent acknowledged the vaccine's importance but did not prioritize it. The remaining respondents scattered across a spectrum of ambivalence and resistance: 10.5 percent felt indifferent, 8.1 percent expressed uncertainty, 6.7 percent showed active disinterest, and 4.8 percent identified openly as anti-vaccine. Among elderly respondents, 62 percent planned to receive the dengue vaccine right away, compared to just 46 percent of younger people.

The findings suggest that the pandemic's end did not restore confidence in vaccination so much as it allowed doubt to take root. For some Brazilians, the urgency that drove mass immunization campaigns during Covid-19 has evaporated. For others, skepticism that may have simmered quietly has now surfaced openly. The regional and generational splits point to uneven access and uneven trust—two problems that no single policy fix can easily solve. As Brazil moves forward, the question is whether these declining rates represent a temporary adjustment or the beginning of a longer erosion in public health infrastructure.

The study was conducted between February and March 2026 via 1,500 telephone interviews with Brazilians aged 16 and older, stratified across gender, income, age, education, social class, region, race, and religion.
— Unifesp's Sou Ciência research center
A Conversa do Hearth Outra perspectiva sobre a história
Inventor

Why did vaccination rates drop so sharply after the pandemic ended? Did people simply feel safer?

Model

Partly, yes. The acute fear that drove people to clinics during Covid-19 lifted. But the data suggests something deeper—about 9.2 percent actively stopped vaccinating after the pandemic, which implies a deliberate choice, not just drift.

Inventor

What about the 30 percent who are now outside the standard? Are they all refusing vaccines, or is it more complicated?

Model

It's fragmented. About a third of that group refuses outright. Another third stopped after the pandemic. The rest didn't answer or are in a gray zone of hesitation. The dengue vaccine numbers show this clearly—70 percent think it's good, but less than 57 percent will actually get it.

Inventor

The regional gap is striking. Why would the North be 15 points behind the Southeast?

Model

Access, mostly. Healthcare infrastructure is thinner in the North. But it's also about trust and information. When vaccination programs are distant or inconsistent, people lose confidence in them.

Inventor

The elderly are vaccinating at much higher rates than young people. Is that just because they remember earlier disease outbreaks?

Model

Likely. They lived through measles, polio, dengue epidemics. They know what these diseases do. Younger people haven't seen that. They see the vaccine as optional, not essential.

Inventor

What worries you most about these numbers?

Model

The 4.8 percent who openly identify as anti-vaccine. That's a small but vocal group. If that sentiment spreads, especially among younger people who already show low engagement, you could see cascading declines in coverage for diseases that are still circulating.

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