If you will travel to Costa Rica from South America or sub-Saharan Africa, you will need the Yellow Fever Vaccine. The countries considered at risk are: Angola, Benin, Burkina Faso, Cameroon, Congo DR, Gabon, Gambia, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, Sudan, Bolivia, Brazil, Colombia, Ecuador, Peru, Guyana, and Venezuela. You must get the vaccine 10 days before your arrival date to Costa Rica. Any individual traveling to Costa Rica that has been in transit, whether in airports, seaports, or land borders, in the following countries, will require a vaccination: Bolivia, Brazil, Colombia, Ecuador, Peru and Venezuela.