How are hiv-1 and hiv-2 different?

Subtypes: Hiv has two major types (in humans), along with several subtypes (called clades) of hiv-1. These clades are given subtypes of letters of the alphabet. These strains can create hybrids: slightly different genetic make-up from one another, sometimes called circulating recombinant forms. For the most part, hiv-2 is more difficult to transmit with a longer incubation period.

Different types: Hiv-1 and hiv-2 are different types of hiv. Hiv-1 comprises the majority of HIV infection in the world. Hiv-2 is usually found in africa, and rarely elsewhere. Both hiv-1 and hiv-2 can usually be detected through the usual hiv-1/2 antibody test. Hiv-2 is typically less aggressive/virulent and less transmissible (more difficult to pass from one person to another).