Passive Immunization Against Monkey HIV Produces Encouraging Results

Active immunization against HIV has not yet produced a viable vaccine. The discovery of broadly neutralizing antibodies against HIV (NEJM JW Gen Med Dec 1 2013 and Nature 2013; 503:224) has generated more enthusiasm for passive immunization.

An international team, led by investigators at NIH, created a “cocktail” of four broadly neutralizing antibodies against HIV and tested its efficacy in monkeys. Immunized monkeys and untreated controls were challenged weekly with repeated low doses of simian HIV to mimic repeated low-dose exposures typical of human infection. The control animals all became infected after 2 to 6 challenges. The treated animals remained virus-free after as many as 23 weekly challenges.