HIV vaccine development

Published on June 30, 2015   46 min

Other Talks in the Series: Vaccines

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Hello, my name is Patricia Fast. I'm a pediatrician who's worked for about 20 years on AIDS vaccines, trying to develop an AIDS vaccine. Currently I'm Senior Technical Advisor for the International AIDS Vaccine Initiative, which is a non-profit dedicated to the proposition that the world needs an AIDS vaccine, and I also teach part-time as an Adjunct Associate Professor at Stanford University.
As soon as the new lentivirus, HIV-1 was discovered in 1984 as the cause of AIDS, there was great hope that a vaccine would soon be discovered. You probably know that lentiviruses are RNA viruses that insert a copy of their genome into the host genome as a way of replicating. There are two HIV viruses, HIV-1 and -2, most of the research has been done on HIV-1, and I'll generally call it in this lecture, HIV. The discovery soon afterward of a related lentivirus that cause AIDS in non-human primates, macaque monkeys, focused attention on this Simian Immunodeficiency Virus, or SIV model. Much later it became evident that focusing on the dominant model, which was a strain of SIV called Mac 239 in rhesus macaques, lead to a bias in the research because SIV 239 is almost impossible to neutralize. So it tended to minimize the importance of neutralizing antibodies, but we'll come back to that. Eventually, a hybrid virus was constructed between HIV and SIV, it's called SHIV, and rhesus monkeys could then be infected with a virus that carries the HIV envelope or the major protein on the surface of HIV, which it uses to access cells. That allowed research into the importance of neutralizing antibodies. A little bit of work was originally done in chimpanzees, which can be infected with HIV but seldom become ill. Antibodies were shown to prevent infection, but because chimpanzees are a protected species, the model was abandoned.