It was always explained that AIDS (acquired immunodeficiency syndrome) was a result of the HIV (human immunodeficiency virus). That said, many top scientists claim that HIV was NEVER proven to exist. Agreed. Gay men in the day were doing poppers and other drugs that had horrific side effects (one being damage to their immune systems). A weak immune system lets all sort of infectious agents operate unencumbered. Thus, acquired immunodeficiency. At least that was one path to it.