HIV vaccine development

Published on June 30, 2015   46 min

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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 nonprofit 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 caused 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 mac239, in rhesus macaques led 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. So 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. But antibodies were shown to prevent infection. But because chimpanzees are a protected species, the model was abandoned.