Yellow fever vaccination (or a medical exemption certificate) is a mandatory entry requirement for Uganda, Kenya and Tanzania if you are arriving from, or have transited through, a country with risk of yellow fever transmission — and increasingly, several East African countries now require proof of vaccination from all arriving travelers regardless of origin, so confirm current entry rules for your specific nationality and routing well before departure, since requirements shift. Routine vaccinations (MMR, tetanus, hepatitis A and B, typhoid) should be current regardless of yellow fever status, and a pre-trip consultation with a travel health clinic 4-6 weeks before departure is genuinely worth the appointment rather than relying on general advice. Malaria risk exists across nearly all of the safari regions covered here, including Zanzibar's coast, and antimalarial medication (several options exist, discuss which suits your medical history with a doctor) alongside consistent evening insect repellent and covering up at dusk is standard, sensible practice, not an overreaction. The Seychelles, by contrast, is malaria-free, which is worth knowing if malaria prophylaxis side effects are a genuine concern for part of your trip. None of this should be alarming — it is routine, well-understood travel medicine that millions of safari travelers navigate every year without incident.