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Immunizations and Antibiotics for Overseas Travel


Immunizations are a method to stimulate the body's immune system to protect itself from diseases. Immunization is done with vaccines made from the infectious virus or bacteria. A vaccine can contain a noninfectious fragment of a virus or bacteria, a weakened live whole organism that does not cause the disease, or a harmful substance that has been modified to make it harmless (toxoid). These immunizations stimulate the immune system to make antibodies so that it can respond when challenged by the real bacteria, virus, or toxin.

When traveling, it is easiest to divide vaccinations into three groups: routine, recommended, and required. Routine vaccinations are those that are recommended by the U.S. Centers for Disease Control and Prevention (CDC) to prevent serious and sometime fatal diseases. Many of these diseases are uncommon today in the United States but can be very common in foreign countries. Although most U.S. citizens have already received these vaccinations, many may not be up-to-date and require boosters. Recommended vaccinations are those vaccinations that can help protect travelers from diseases that are found in other parts of the world, specific to the countries the traveler will visit. The only vaccinations required by the International Health Regulations are yellow fever for travel to certain countries in sub-Saharan Africa and tropical South America and meningococcal vaccination for travelers to Saudi Arabia during the Hajj (the Muslim pilgrimage to Mecca).

Routine vaccinations in the U.S. include the following:

Recommended vaccinations for travel (depending on which countries are being visited)

  • Japanese encephalitis
  • Rabies
  • Typhoid
  • Meningococcus (unless already received as part of routine vaccinations)
  • Hepatitis A (unless already received as part of routine vaccinations)

Required vaccinations

  • Yellow fever: certain countries in sub-Saharan Africa and tropical South America
  • Meningococcal vaccination for travelers to Saudi Arabia during the Hajj

All vaccination series can be started on the same day. The lead time for immunization depends on the types of vaccinations needed. Some vaccination courses can take up to six months (such as hepatitis B) to receive all of the required shots. In addition, live-attenuated (weakened) viral vaccines must be spaced a month apart and can affect skin testing for tuberculosis.

Moderate-to-severe illnesses can delay immunizations, but people with mild illnesses can still be vaccinated.

The CDC has a web site with the latest information on what immunizations are required for travel to specific countries (
). The site also contains information on travel notices in effect and links to the State Department web site with security information about each country. The site also contains country-specific information on malaria risk and whether or not malaria prophylaxis is recommended.

Many health departments will help travelers to get their vaccinations needed for travel, and in many larger cities, there are travel clinics that only address travel medicine.

Last Reviewed 11/20/2017

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