evidence: Yellow fever vaccination required if coming from or transiting for more than 12 hours through Brazil. [...] Immunizations: Visit the CDC Traveler website for vaccination information, including Yellow Fever vaccination requirements. Carry your International Certificate of Vaccination (or yellow card) with you upon arrival or departure. [...] Vaccinations: Be up to date on all vaccinations recommended by the U.S. Centers for Disease Control and Prevention. A Yellow Fever vaccination is required if coming from or transiting for more than 12 hours through Brazil. Carry your International Certificate of Vaccination (or yellow card) with you upon arrival.