Brazil does not require proof of immunization for entry into the country. Although it is strongly recommended, vaccination is not mandatory for foreigners. However, the country’s health authorities recommend that international tourists update their vaccination status before arriving in Brazil.
The Ministry of Health (MS) points out that it is ideal to follow the vaccination schedule guidelines of the country of origin or residence, particularly vaccines against COVID-19, yellow fever, polio, measles and rubella, diphtheria, and tetanus.
Amazonas is an Area with Recommended Vaccination (ACRV) for yellow fever. Therefore, the yellow fever vaccine is recommended for residents and/or travelers heading to ACRV areas, at least 10 days before the travel date, the time required for the vaccine to provide protection against infection.
Anyone who has already been vaccinated at least once against yellow fever (with the standard/unfractionated dose) does not need to receive a new dose. The evaluation of the vaccine showed that a single dose is sufficient to protect against the transmission of the disease. Since 2014, the World Health Organization (WHO) changed its guidance when it concluded that a booster dose is not necessary to maintain protection against the disease, and in early 2022 Brazil adopted the WHO recommendation.
Therefore, it is strongly recommended that foreign tourists come to Brazil with a complete vaccination schedule for COVID-19, diphtheria, tetanus, and polio, in accordance with the recommendations in their country of origin and in those where they will make connections.
https://www.gov.br/saude/pt-br/assuntos/saude-de-a-a-z/s/saude-do-viajante/vacina-para-viajantes