Broadly Neutralizing Antibodies Against HIV: Potent and Persistent

Studies of passive immunization with conventional anti-HIV antibodies have been disappointing: High mutation rates of HIV allowed antibody-resistant strains to form. The subsequent discovery of antibodies that neutralize most HIV strains in vitro (JW Gen Med Oct 13 2011) was greeted with excitement, because it suggested that passive immunization therapy could work in vivo.

Now, an international team has studied this approach in HIV-infected humanized mice (which have a human hematopoietic system). A combination of five broadly neutralizing antibodies — each of which targets a different HIV antigenic epitope — was given subcutaneously once or twice weekly for as long as 1 month. Viral load dropped below detectable levels, and this control of …