Hepatitis A is probably the most useful vaccine to receive if you’re going to a developing country. The vaccine is almost 100% effective and has a protective lifespan of over 30 years once the two initial doses are given. Hepatitis A is also found in the United States, so receiving the vaccine will not only protect you from foreign exposure to the virus but domestic exposure, too.
The Hepatitis B vaccine is now required for all children in the United States, but most adults haven’t been vaccinated. Although the virus usually spreads through blood or sexual contact, if you have plans for a prolonged stay overseas or believe you’ll need medical assistance for chronic conditions while abroad, it’s advisable to receive the Hepatitis B vaccine. There is also a combination vaccine, Twinrix, which protects against Hepatitis A and Hepatitis B, all in one shot.
While the meningococcal vaccine is a requirement for college students to enter a school, there are certain parts of the world where there are yearly outbreaks of this type of fatal meningitis — particularly in sub-Saharan Africa. If you’re traveling to these areas, this vaccine is recommended.
The rabies vaccine is usually only necessary if a great deal of adventure travel is planned, or if you’re going to be working with animals who may have rabies. It’s important to remember that many domestic cats and dogs are not vaccinated against rabies in other countries — try to avoid contact with them.
Although there has been a worldwide eradication effort of polio in place for the last several years, two new areas with polio outbreaks are Yemen and Nigeria. Determining when to get the polio vaccine is an ever-changing debate, but if you’re going to Africa or Asia, one booster shot as an adult is all that’s required.
Finally, if you’re going to the tropics, Alaska over the summer, or the Southern Hemisphere during their winter (our summer), you should also receive the flu shot. The vaccine is usually available through June in the United States, but if you’re in a very high-risk group, you can also receive the vaccine when you arrive at your destination.