Question: What is (are) Yellow Fever Vaccination ?
Answer: If you continue to live or travel in yellow fever-endemic areas, you should receive a booster dose of yellow fever vaccine after 10 years. After receiving the vaccine, you should receive an International Certificate of Vaccination (yellow card) that has been validated by the vaccination center. This Certificate becomes valid 10 days after vaccination and lasts for 10 years. You will need this card as proof of vaccination to enter certain countries.
Source: CDC