Gabon is a tropical equatorial country, and you need to take health precautions seriously.
Yellow fever vaccination is mandatory. You will be asked for proof of vaccination on arrival, and you will not be admitted without it. Get vaccinated at least ten days before travel.
Malaria is present throughout the country, including in Libreville. Take prophylaxis, use insect repellent, and sleep under a treated mosquito net. This is not optional. Malaria is the leading cause of illness among travelers to Gabon.
Other recommended vaccinations include hepatitis A, hepatitis B, typhoid, and routine boosters. Rabies vaccination is worth considering if you plan to spend time in rural areas or around wildlife.
Medical facilities are limited. Libreville has a few hospitals and clinics with reasonable capacity, but outside the capital, medical care is basic at best. Bring a comprehensive first aid kit and any prescription medications you need, as pharmacies outside Libreville may not stock what you require. Medical evacuation insurance is strongly recommended.
Tap water is not safe to drink anywhere in Gabon. Stick to bottled or purified water.
The sun is intense at the equator. Sunscreen, a hat, and staying hydrated are essential, even on overcast days.
HIV prevalence is moderate. Standard precautions apply.