Yellow fever is the only disease expressly listed in the International Health Regulations (IHR) for which countries can require proof of vaccination from travellers as a condition of entry into a country . The IHR stipulate that vaccination with a WHO approved yellow fever vaccine provides protection against infection for 10 years, and that the certificate of vaccination or re-vaccination is accordingly valid for 10 years.

The WHO World Health Assembly in May 2014 adopted an amendment to Annex 7 of IHR , which stipulates that the period of protection afforded by yellow fever vaccination, and the term of validity of the certificate will change from 10 years to the duration of the life of the person vaccinated. This change will enter into force legally in July 2016.

The requirement of a proof of vaccination from travellers as a condition of entry into a country shall not be more restrictive of international traffic and not more invasive or intrusive to persons than reasonably available alternatives that would achieve the appropriate level of health protection. In determining whether to implement the requirement of a proof of vaccination from travellers, countries shall base their determinations upon scientific principles, available scientific evidence of a risk to human health, or where such evidence is insufficient, the available information including from WHO and other relevant intergovernmental organizations and international bodies; and any available specific guidance or advice from WHO. A country implementing a requirement of a proof of vaccination which significantly interferes with international traffic shall provide to WHO the public health rationale and relevant scientific information for it. WHO shall share this information with other countries and may, where appropriate, request that the country concerned reconsider the application of the measures.