After 40 years of AIDS, here’s why we still don’t have an HIV vaccine

The complex biology of HIV makes the virus a tough target to tackle

a photo of a protest in Washington, D.C.

The early days of the HIV pandemic in the United States were fraught with controversy as some people saw AIDS as a disease that affected only the gay community. In July 1983,  people marched in Washington, D.C., to demand the funds to fight HIV/AIDS.

Mark Reinstein/Alamy Stock Photo

Forty years ago, researchers described the mysterious cases of five gay men who had fallen ill with a pneumonia caused by the fungus Pneumocystis carinii.