Why don people infected with HIV immediately develop clinical AIDS?
HIV is only one of many viruses that produce an acute symptomatic infection, then may have a long period where the infected person experiences few no symptoms, then later in life develops symptoms again. Examples include: chicken pox, which causes an acute infection and then after decades without symptoms leads to shingles in about 1/7 of infected people; recurring oral herpex simplex (“cold sores’) which may go a long time with no symptoms and then recur; etc. The reasons for these asymptomatic periods can be completely different. The chicken pox virus (varicella-zoster virus) and herpes simplex virus type 1 remain dormant in the nerves and can reactivate causing localized shingles or cold sores respectively. HIV usually appears asymptomatic because the body’s immune system is holding it at bay, generating new CD4 cells as fast as HIV kills them. When the body falls behind in this running battle, HIV can progress to clinical AIDS.
