Study finds HVTN 505 vaccine recognizes, won't neutralize HIV
The vaccine proved to be ineffective, even though it did produce HIV antibodies. The vaccine successfully provoked an immune response against HIV and microbes that are typically located inside the body’s intestinal tract.
The scientists have suggested that the antibodies are a result of the vaccine increasing existing antibody response against the intestinal microbiome. This could be why the vaccine candidate in the HVTN 505 trial did not show positive results.
The HVTN 505 trial used a new investigational vaccine regimen. The trial’s volunteers received a prime or initial vaccine, then later received a second, or booster, vaccine.
In the latest study, the scientists looked at samples from the participants with the prime-boost regimen. The researchers saw that many of the vaccine-induced antibodies could recognize gp41, an HIV surface protein, but the antibodies did not act to effectively neutralize HIV. Rather, the antibodies recognized other proteins that are related to HIV bacteria.
This discovery is part of an ongoing vaccine research effort for vaccines against infectious diseases such as HIV.