Depending on their destination abroad, travelers may need to show proof that they were immunized against certain diseases. It is a good idea to check with representatives of the countries they intend to visit to make sure they comply with any immunization requirements they may have. The requirements vary based on specific diseases. Travelers may find that countries with more tropical climates may require international certificates of vaccination against yellow fever and cholera. Generally, typhoid vaccinations are not required for international travel, but may be recommended for countries where there is a risk of exposure. Smallpox vaccinations are not required anywhere. And it is a good idea for travelers to check their health care records to make sure that their measles, mumps, rubella, polio, diphtheria, tetanus, and pertussis immunizations are current. Preventative measures are advisable for certain areas, such as quinine in areas prone to outbreaks of malaria. Regardless of where U. S. citizens travel, the United States currently requires no immunizations for citizens returning from travel abroad.

If travelers must receive vaccinations, they should keep a record of them on approved forms. An increasing number of countries require that people entering their countries be tested for Human Immune deficiency Virus (HIV) prior to entry. The HIV test is usually included in a medical exam for long term visitors (i.e., students and workers). Before people travel abroad, check with the embassy or consulate of the country that they intend to visit to learn about the health or immunization requirements for visiting their countries, and whether they require an AIDS/HIV test as a condition to enter their countries.