Start two types of HIV

1. HIV-1: HIV-1 is the most common and widespread type of HIV. It is responsible for the majority of HIV infections globally. The virus attacks CD4 cells, which are a type of white blood cells that play a crucial role in the immune system. HIV-1 can progress to AIDS if left untreated.

2. HIV-2: HIV-2 is a less common type of HIV, predominantly found in West Africa. It is similar to HIV-1 in terms of transmission and progression to AIDS, but it generally progresses more slowly. HIV-2 is less infectious and less efficiently transmitted from person to person compared to HIV-1. However, it can still cause severe illness and complications if left untreated.