- There is a large, ongoing outbreak of yellow fever in multiple states of Brazil. Since early 2018, a number of unvaccinated travelers to Brazil contracted yellow fever; many of these travelers were infected on the island of Ilha Grande (Rio de Janeiro State). Several have died.
- Travelers to Brazil should protect themselves from yellow fever by getting yellow fever vaccine at least 10 days before travel, and preventing mosquito bites.
- In addition to areas in Brazil where yellow fever vaccination has been recommended since before the recent outbreaks, the vaccine is now also recommended for people who are traveling to or living in: All of Espirito Santo State, São Paulo State, Rio de Janeiro State, Paraná State, Santa Catarina State, and Rio Grande do Sul State, as well as a number of cities in Bahia State.
- People who have never been vaccinated against yellow fever should avoid traveling to areas of Brazil where yellow fever vaccination is recommended.
- Travelers going to areas with ongoing outbreaks may consider getting a booster dose of yellow fever vaccine if it has been 10 or more years since they were vaccinated.
- Yellow fever vaccine is available at a limited number of clinics in the United States, so travelers should plan ahead to get the vaccine.