A vaccine regimen that first primed the immune system and then boosted it to increase the response could ultimately turn out to be the strategy for protection against the global human immunodeficiency virus (HIV-1) infection, according to new research.
Records showed that there were already 35 million people around the world who were infected with HIV, which caused AIDS.
The phase 1/2a study (HIV-V-A004) was now enrolling 400 volunteers in the US and Rwanda for evaluation of the heterologous prime-boost regimens, with sites in South Africa, Uganda and Thailand opening soon.
Since it started spreading 30 years in the past, AIDS had killed 40 million individuals worldwide.
Despite progress in treatments, according to experts, a vaccine was the best hope for eradicating the disease. It first involved priming the immune system using the weakened version of the cold virus to inject HIV genes to the body.
According to Dr Paul Stoffles from Johnson & Johnson, which collaborated on the research, the ultimate aim of the researchers was to develop a vaccine that prevented HIV in the first place, Reuters reported.
The vaccine had completely prevented HIV infection in half of monkeys given the jab.
According to Stoffels, the HIV vaccine trial in monkeys was designed to test the limits of the vaccine, even as it exposed the animals to high levels of an aggressive virus that attacked non-human primates known as simian immunodeficiency virus, a close cousin to HIV.
The results were so encouraging that they spurred Johnson & Johnson to test the vaccine in people.
It was the first time since Merck's failed 2007 trial that a major pharmaceutical company had sponsored clinical development of an HIV vaccine, according to Dr Dan Barouch, a vaccine researcher at Beth Israel Deaconess Medical Center and the Ragon Institute of Massachusetts General Hospital, MIT and Harvard.
The company was using the same prime-boost strategy in its Ebola vaccine, now in early-stage human trials.
The virus was potent enough to infect 100 per cent of unvaccinated animals following six exposures, but despite that half of the animals who got the vaccine were completely protected.
According to Dr Stoffels the infection rate per exposure in the trial was about 100 times greater than what was typically seen in humans.
Though Johnson & Johnson expected the vaccine to prove even more effective in people, even if the vaccine only protected half of those people who got it, it would still have an enormous public health impact according to Stoffels.