Washington DC: A team of US researchers have revealed that a five-part investigational vaccine may protect monkeys from HIV-like virus to 55 percent.
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.
Researchers from Duke University Medical Center in Durham said the improved vaccine added three more targets to a human vaccine candidate that showed a promise.
The team used a more-is-better approach in monkeys that appeared to improve vaccine protection from an HIV-like virus.
Senior study author Barton F Haynes,"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."
Haynes added,"In this study in monkeys, we increased that level of protection to 55 percent by using a pentavalent (five-part) vaccine."
The researchers -- including Bette T. Korber 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, Haynes said.
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.
Lead study author Todd Bradley."Vaccine protection using this model of virus infection in primates is possible."
Bradley stated,"This is a proof-of-concept that provides a strategy to improve upon the first HIV vaccine regimen that provided limited protection in people."
The study is published online in the journal Nature Communications.
(With ANI inputs)