Travelers from at-risk countries who are older than 60 or younger than 9 months are exempt from the yellow fever vaccination requirement, as are pregnant or lactating women. Other exemptions include people with asymptomatic HIV infection, thymus diseases, or egg or gelatin allergies, according to the World Health Organization's International Travel and Health website.
The WHO site recommends that travelers to Limon province protect themselves against malaria by taking chloroquine chemoprophylaxis and avoiding mosquito bites. MDTravelHealth.com says other anti-malarial drugs such as mefloquine, atovaquone/proguanil, doxycycline and primaquine are also acceptable.
MDTravelHealth.com recommends a Hepatitis B vaccine for all travelers to Costa Rica and a Hepatitis A vaccine for all travelers over one year of age.
The U.S. Centers for Disease Control and Prevention's Travelers' Health website recommends a typhoid vaccine for all unvaccinated people traveling to Central America, especially those visiting smaller cities or rural areas.
According to the CDC, travelers should see a health care provider four to six weeks prior to departure to give the vaccines and/or malaria medication time to take effect.
