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Two F1000 Faculty Members last month alerted us to some exciting news in the challenging sphere of HIV research. Led by Nobel Laureate David Baltimore, biologists at Caltech have been pioneering a new approach in HIV vaccination called vectored immunoprophylaxis (VIP).

Their research, published in Nature, veered away from traditional vaccination methods that introduce the HIV virus in order to provoke an immune response via infection-fighting antibodies or a T cell-mediated attack. These methods, Baltimore says, are not working and the problem requires a new way of thinking.

“Rather than trying to use a virus as a vaccine, we decided to take antibodies that had already developed and see if we could make people [or rather, humanized mice] produce those antibodies as protection.”

David Baltimore talks about his pioneering research:

Their results indeed showed that, by injecting humanized mouse muscle cells with a modified viral vector optimized for the production of HIV-neutralizing antibodies, the animal was subsequently protected against HIV infection, even when challenged with very large viral doses. This VIP approach in mice has, in fact, resulted in “lifelong expression of these monoclonal antibodies at high concentrations from a single intramuscular injection”.

The study was evaluated by Faculty Members Yufei Wang and Jay Rappaport. Wang, who studies HIV infection and AIDS at King’s College London, is hopeful about the ramifications of this work:

“Since there is currently no effective vaccine to prevent HIV infection, this study using vectors that express available identified broad HIV-neutralizing antibodies to bypass the adaptive immune system may hold promise as an alternative approach to an effective HIV vaccine.”

As is Rappaport, a researcher at Temple University School of Medicine, who commented that “This work has direct implications for translation to human studies. Furthermore, this work also has implications for more conventional immunization strategies which would elicit responses targeting the b12 epitope.”

However, David Baltimore advises caution in extrapolating these findings to a clinical setting:

“The history of vaccine research is that humans don’t behave like mice, and so we have to be prepared for surprises in carrying this work back to humans, and we may have to go back to the laboratory and solve new problems…”

Still, this is a very positive step forward in HIV research, clearly demonstrating that VIP has an advantage over standard vaccination: “it simply works”.