International travel and health

Yellow fever risk mapping and recommended vaccination for travellers

The scientific and technical advisory group on geographical yellow fever risk mapping (GRYF)


At the World Health Assembly in May 2015, the Director-General was requested to establish a formal scientific and technical advisory group on geographical yellow fever risk mapping, with the participation of countries with areas at risk of yellow fever:

    - to maintain up-to-date yellow fever risk mapping; and

    - to provide guidance on yellow fever vaccination for travellers in ways   that facilitate international travel.


The scientific and technical advisory group on geographical yellow fever risk mapping consists of experts with scientific expertise and practical experience in public health, travel health and yellow fever. The members are some of the leading experts in the world in their respective fields and act in their personal capacities.

This group meets via teleconference at least once each year or upon request of the Secretariat on an ad hoc basis. The Secretariat may invite the State to the teleconference where the yellow fever risk classification is being reviewed to present its views to the advisory group. Moreover, States may submit a request to the WHO Secretariat to revise its yellow fever risk classification. This request should be documented with a public health justification and scientific data.

For further information on evidences required please consult the WHO technical guidance on Risk assessment on yellow fever virus circulation in endemic countries, available in English and French online.


Advise of the geographical yellow fever risk mapping group is reflected in the International Travel and Health, Annex 1 listing countries with risk of yellow fever transmission and countries requiring yellow fever vaccination.

Background, rationale for establishment of this group as well as scope of work, functions and procedures are further described in the Terms of Reference.