Hi Dennis, What occurred recently was that WHO confirmed that the protection against the disease provided by a single dose of yellow fever vaccine is lifelong, something that was recognised for some time but not "official". It is now official.
However, this does not mean that one shot will be enough for entry requirements to certain countries, as the International Certificate is still only valid for 10 years, and until all the countries agree to change the rule, the requirement to have to repeat the vacine for the purpose of a valid certificate remains. Hopefully this may occur in next couple of years. Incidently, the risks associated with older people ( >65Y) getting the vaccine which are troublesome, do not apply to second vaccination, so there are no health issues about getting a second or third vaccine.Close X