Consider a country not on the list

Yellow fever vaccine is in a world wide shortage and over the next two years it will be increasingly difficult to obtain.

The African Countries:

Angola, Benin, Burundi, Cameroon, Central African Republic, Chad, Congo, Republic of the Cote d'Ivorie (Ivory Coast), Democratic Republic of the Congo, Congo, Equatorial Guinea, Ethiopia, Gabon, The Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Mali, Mauritania, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, Sudan, Togo, Uganda, Eritrea, Sao Tome, Somalia, Tanzania, Zambia

The South American Countries:

Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Suriname, Trinidad and Tobago, Venezuela

How about South Africa in lieu of Kenya, plenty of safaris in South Africa!

Yellow fever is good for life. It has changed recently and if you have a yellow fever card that indicates the expiry date as ten years from when you received the vaccine you don't need to replace it.