Yellow fever
Yellow fever is the most common vaccine required for international travel. Many countries require the vaccine for all travellers or only for travellers coming from countries with risk of yellow fever transmission. Exceptions are typically made for newborns until 9 months or one year of age, depending on the country. The ICVP form is valid for yellow fever starting 10 days after vaccination. As of 2016, the vaccine is valid for the life of the traveller. No changes need to be made for those who received their vaccine or ICVP prior to 2016.