viral infectivity factor (Vif)

Viral infectivity factor (Vif) is a protein produced by HIV that helps the virus infect and replicate within human cells. Vif's main role is to neutralize a natural defense mechanism in the immune system—proteins called APOBEC3 enzymes—that would otherwise incorporate into the virus and damage its genetic material, preventing infection. By stopping APOBEC3 proteins, Vif allows HIV to produce healthy new viruses capable of spreading. Without Vif, HIV's ability to infect cells and replicate efficiently is greatly reduced, making it a key target for research and potential therapies.