(Last updated 9/29/2013; last reviewed 9/29/2013)
Vaccines are products designed to protect people from disease. There are vaccines against many diseases, for example, chicken pox, flu, and polio. The process of getting a vaccine is called vaccination or immunization.
Most vaccines are designed to prevent a person from ever having a particular disease or to only have a mild case of the disease. When a person gets a vaccine (by needle injection, by mouth, or by aerosol spray), the body responds by mounting an immune response against the particular disease. An immune response includes all the actions of the immune system to defend the body against the disease-causing bacteria, virus, or other foreign organism.
Vaccines not only protect individuals from disease, they protect communities as well. When most people in a community get immunized against a disease, there is little chance of a disease outbreak.
Testing is underway on experimental vaccines to prevent and treat HIV/AIDS, but no HIV vaccine is approved for use outside of clinical trials. Even though there isn’t a vaccine to prevent or cure HIV, people with HIV can benefit from vaccines against other diseases.
Yes. Damage to the immune system due to HIV can reduce the body’s immune response to a vaccine. A weakened immune response makes a vaccine less effective. In general, vaccines work best when an HIV-infected person’s CD4 count is above 200 copies/mm3.
By stimulating the immune system, vaccines may also cause a person’s level of HIV (viral load) to increase temporarily.
Because HIV medicines strengthen the immune system and reduce HIV viral load, people with HIV may want to start antiretroviral therapy (ART) before getting vaccinated whenever possible. In some situations, however, immunizations should not be delayed to start ART. For example, it’s important for people with HIV to get vaccinated against the flu at the time of year when the risk of flu is greatest.
The design of a vaccine depends on several factors, such as how a microbe infects the body and how the immune system responds. For this reason, there are several types of vaccines, including live, attenuated vaccines and inactivated vaccines.
A live, attenuated vaccine contains a weakened but live form of a disease-causing microbe. Although the attenuated (weakened) microbe cannot cause the disease (or can cause only mild disease), the vaccine can still trigger an immune response.
Inactivated vaccines are made from microbes that have been killed with chemicals, heat, or radiation. There is no chance that an inactivated vaccine can cause the disease it was designed to prevent.
In general, to be safe, people with HIV should get inactivated vaccines to avoid even the remote chance of getting a disease from a live, attenuated vaccine. However, for some diseases, only live, attenuated vaccines are available. In this case, the protection offered by the live vaccine may outweigh the risks. Vaccines against chicken pox and shingles are examples of live, attenuated vaccines that, in certain situations, may be recommended for people with HIV.
In general, side effects from vaccines are minor (for example, a sore arm or low-grade fever) and go away within a few days. Severe reactions to vaccines are rare. Before getting a vaccine, talk to your health care provider about the benefits and risks of the vaccine and possible side effects.
The following vaccines are recommended for people with HIV:
Regardless of destination, all travelers should be up to date on routine vaccinations. Those traveling to destinations outside the United States may need immunizations against diseases present in other parts of the world, for example, cholera or yellow fever.
If you have HIV, talk to your health care provider about any vaccines you may need before you travel. If a required immunization is only available as a live, attenuated vaccine, your health care provider can give you a letter that excuses you from getting the vaccine. If your CD4 count is less than 200 copies/mm3, your health care provider may recommend that you delay your trip to give HIV medicines time to strengthen your immune system. To prepare for your trip, read information from CDC on Travelers with Weakened Immune Systems.