For travel to Kenya in 2026, the requirement for a Yellow Fever vaccine depends primarily on your travel history. Kenya is considered a "high-risk" country for Yellow Fever, so the vaccine is strongly recommended for all travelers over 9 months of age for their own protection. From a legal entry standpoint, you MUST provide an International Certificate of Vaccination (Yellow Card) if you are arriving from a country with a risk of Yellow Fever transmission (including layovers of more than 12 hours in airports of such countries). If you are flying directly from a non-risk country like the United Kingdom, United States, or India, the vaccine certificate is technically not required for entry, but customs officials occasionally ask for it anyway. Because the vaccine must be administered at least 10 days before arrival to be valid, it is best to get it regardless of your route to avoid potential quarantine or entry denial, especially if you plan to visit other African or South American countries on the same trip.