Required if you are travelling from, or have recently visited a country with risk of Yello Fever transmission (All persons above one year of age). The certificate is valid for ten years. Countries considered to be at risk are:
Africa: Angola, Benin, Burkina Faso, Burundi, Cameroon, CAR (Central African Republic), Chad, Republic of Congo, the Democratic Republic of the Congo, Equatorial Guinea, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Kenya, Liberia, Mali, Mauritania, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, South Sudan, Sudan, Togo and Uganda.
Americas: Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Surinam, Trinidad and Tobago, Venezuela
If you have been advised against the Yellow Fever vaccine by your medical practioner you should request a waiver. However this waiver is no guarantee that you will still be allowed into the country