Yellow fever vaccine is required for travellers to affected areas in Africa and South America (CDC maps of Yellow Fever regions) and significant outbreaks continue (see Lancet: Yellow Fever: a global reckoning). There have been recent changes in vaccination requirements, with many countries now accepting life-long validity of yellow fever certificate. This is in line with WHO Health Assembly recommendations effective from June 2016, following reviews which found a single dose of the vaccine offers protection for life.
The Australian Government is adopting the WHO amendment for the yellow fever vaccine from the 16th of June 2016, with current border control processes in place until this time (Department of Health: Yellow Fever factsheet).
Clinicians can consult the list of the yellow fever certificate requirements for individual countries, including the current accepted period of validity for yellow fever vaccination certificates, on the recent “International Travel and Health” WHO publication (Yellow Fever vaccination requirements by destination)