Start with the CDC page
The Centers for Disease Control and Prevention keeps a page for every destination that lists required vaccines, recommended vaccines, malaria risk and current outbreaks. The lead time matters because several vaccines are given as a series and most need about two weeks to produce full protection. If you are leaving sooner than that, go anyway, since partial protection and good advice beat none.
The usual shots
The first job is confirming that your routine vaccines are current, particularly measles, tetanus and the seasonal flu shot. Measles is far more common abroad than at home. Hepatitis A and typhoid are the standard additions for much of Asia, Africa and Latin America, because both travel in food and water. Yellow fever is the special case: some countries in Africa and South America will not admit you without the stamped International Certificate of Vaccination, known as the yellow card. The vaccine is given only at authorized clinics, at least ten days before arrival. Travel vaccines are often not covered by insurance and can run to several hundred dollars, so ask for prices when you book.
Malaria and mosquitoes
Malaria protection for travelers is a prescription tablet, started before the trip and continued after it, and the right drug depends on the region. Take it exactly as prescribed. Dengue, Zika and chikungunya have no such pill, so preventing bites does the work. Use a repellent containing DEET at 20 to 30 percent or picaridin, wear long sleeves at dawn and dusk, and choose a room with screens or air conditioning.
Your own medicines
Carry prescriptions in their original labeled containers, in your carry-on, with enough for the trip plus a week. Bring a copy of each prescription showing the generic name. Some countries restrict medicines that are ordinary at home, including certain stimulants, strong painkillers and some decongestants, so check with the destination's embassy before you pack them.
When you get sick anyway
Traveler's diarrhea is the most common illness, and most cases pass in a few days with rest and fluids. Oral rehydration salts, sold in pharmacies everywhere, replace what you lose better than water alone. See a doctor for blood in the stool, a high fever or symptoms that last beyond three days. Any fever during or after a trip to a malaria region, even months later, needs same-day medical attention and a mention of where you have been.
Note Medicare generally pays nothing for care abroad, and many private US plans cover only emergencies there. Find out what yours covers before you leave.
