⚠ Data for the years 2021 & 2022 are preliminary. Due to the impact of the COVID-19 pandemic, data for the year 2020 should be interpreted with caution.
COVID-19 disruptions in HIV diagnosis, care and reporting of deaths during 2020 have also made incidence, prevalence, and knowledge of status estimates derived from a CD4-based model, unreliable. Therefore, a 2020 edition of the HIV Surveillance Supplemental Report “Estimated HIV Incidence and Prevalence in the U.S.”, which provides data on estimated incidence, prevalence, and knowledge of status in the U.S., was not published by CDC.

HIV | AHEAD

Glossary

Learn more about the terminology used in the Ending the HIV Epidemic: A Plan for America initiative.

Click on a term to view its definition.

HIV

“HIV” stands for human immunodeficiency virus. It is the virus that can lead to acquired immunodeficiency syndrome or AIDS if not treated. Unlike some other viruses, the human body can’t get rid of HIV completely, even with treatment. So once you get HIV, you have it for life.

HIV attacks the body’s immune system, specifically the CD4 cells (T cells), which help the immune system fight off infections. Untreated, HIV reduces the number of CD4 cells (T cells) in the body, making the person more likely to get other infections or infection-related cancers. Over time, HIV can destroy so many of these cells that the body can’t fight off infections and disease. These opportunistic infections or cancers take advantage of a very weak immune system and signal that the person has AIDS, the last stage of HIV infection.