Brazilian flu vaccine put to the test against global standard
NCT ID NCT03777163
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This completed Phase 4 trial tested whether the Butantan Institute's seasonal flu vaccine is as safe and effective as the Sanofi vaccine. A total of 632 Brazilian adults aged 18 to 69 received one of the two vaccines. Researchers measured immune response through blood tests and tracked side effects like pain, fever, and fatigue for up to 21 days after vaccination.
What this could mean
Our plain-language read of the trial. This is informational only — not medical advice or a prediction.
- Active substance
- Trivalent seasonal influenza vaccine (inactivated, split-virion, egg-based)
- What this could lead to
- If successful, this could confirm that the Butantan flu vaccine is as safe and effective as the Sanofi vaccine, offering a reliable alternative for seasonal flu prevention.
- What could go wrong
- This is a completed Phase 4 trial, so results are already in. However, the study only included adults in Brazil, so findings may not apply to other populations or age groups.
This is an AI summary of the original study and may miss details. Read our disclaimer.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Centro de Pesquisas Clínicas do Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo
São Paulo, São Paulo, 05403 000, Brazil
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Centro de Referência de Imunobiológicos Especiais (CRIE) Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo
São Paulo, São Paulo, 05403-000, Brazil
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Centro de Referências para Imunobiológicos Especiais da Universidade Federal de São Paulo
São Paulo, São Paulo, 01220200, Brazil
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Unidade de Pesquisa Clínica do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo
Ribeirão Preto, São Paulo, 14049900, Brazil
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