Many studies have shown that 17D vaccine is highly immunogenic.
Protective antibodies take 7–10 days to develop.
Neutralizing antibody, a correlate of protection, is seen in more than 90% of vaccinees within 10 days and in 99% of vaccinees within 30 days. Consequently, the vaccine should be administered at least 10 days before the traveler visits an area with risk for yellow fever virus transmission.
Revaccination has been required by certain countries at 10-year intervals to comply with International Health Regulations (IHR). In 2014, the World Health Assembly (of WHO) adopted the recommendation to remove the 10-year booster dose requirement from the IHR as of June 2016. Once this change is instituted, a completed International Certificate of Vaccination or Prophylaxis will be valid for the lifetime of the vaccinee. It is uncertain when and if all countries with yellow fever vaccination entry requirements will adopt this change.
In the United States, the Advisory Committee on Immunization Practices (ACIP) is considering the issue of the continued need for yellow fever vaccine boosters. Until ACIP issues updated recommendations, CDC recommends that US travelers receive booster doses of yellow fever vaccine every 10 years if traveling to an area with risk of exposure to yellow fever virus. For the most up-to-date information about yellow fever vaccine boosters, consult the CDC Travelers' Health website.