According to a study by the US researchers which was published online in the Journal Nature Communications, a five-part investigational vaccine may protect monkeys from HIV-like virus to 55 percent. The researchers from Duke University Medical Center in Durham said that the vaccine added three more targets to a human vaccine candidate that showed a promise. Adding three more targets to the investigational vaccine for a total of five, more than half of the vaccinated animals were protected from simian-human immunodeficiency virus infection. The team used a more-is-better approach in monkeys that appeared to improve vaccine protection from an HIV-like virus.
"The vaccine regimen tested in the Thai trial, known as RV144, had a 31 percent efficacy and is the only HIV investigational vaccine regimen to have demonstrated even modest protection from HIV infection. In this study in monkeys, we increased that level of protection to 55 percent by using a pentavalent (five-part) vaccine " said senior study author Barton F. Haynes.
Bette T. Korber, a researcher of the Los Alamos National Laboratory, who led the vaccine design -- started from the foundation used in the RV144 human vaccine trial in Thailand, adding targets that elicited antibody responses to regions of the HIV envelope.
Those antibodies were fairly easy to induce, said Haynes.
By adding the three additional regions of the viral envelope to the investigational vaccine, the researchers improved the level of protection afforded to animals exposed to a difficult-to-neutralise strain of the simian virus, which is comparable to HIV.
"Vaccine protection using this model of virus infection in primates is possible," said lead study author Todd Bradley.
"This is a proof-of-concept that provides a strategy to improve upon the first HIV vaccine regimen that provided limited protection in people," Bradley stated.
