Dr. Dan Barouch, Professor of Medicine at Harvard Medical School and author of the study, told Newsweek he is "cautiously optimistic" about the results, but stressed there are many obstacles to overcome before a vaccine is rolled out for humans. This vaccine is one of the five experimental HIV-1 vaccine concepts that reached such a success in nearly 40 years of HIV pandemic.
An experimental HIV vaccine showed promise of protecting healthy adults from contracting the deadly virus that killed millions of people in the past years.
Comparatively, the new HIV vaccine yielded better immunization rate and virtually no side effects.
One of the biggest challenges is the fact that many vaccine candidates that seem to work in the lab or in animal trials often don't work in human trials, which means a lot of time and money can be spent developing something that doesn't actually work.
An HIV vaccine under development by scientists has passed through to the next phase, creating hope for a future after more than 40 years of research and development.
An experimental HIV vaccine was safe and triggered strong immune responses in healthy adults and in monkeys, researchers report.
In a parallel study, the researchers assessed the immunogenicity and protective efficacy of the same Ad26-based mosaic vaccine regimens in 72 rhesus monkeys using a series repeated challenges with simian-human immunodeficiency virus (SHIV) - a virus similar to HIV that infects monkeys.
In total, it's approximated that almost 80 million people have been infected since the HIV virus was first detected in the early 1980s - and 35 million have died.
The results, which were published last week, showed that all the vaccine regimens generated an anti-HIV immune response, and were well tolerated. Currently, around 37 million people are living with HIV/Aids across the world: levels that amount to a pandemic.
"Despite all the advances we have had with HIV, we need a vaccine".
They say it also protected two-thirds of monkeys against an HIV-like virus. They got four vaccinations over the span of 48 weeks.
Inventing a vaccine has proved an vast challenge for scientists, in part because there are so many strains of the virus, but also because HIV is adept at mutating to elude attack from our immune systems.
All of the vaccine combinations produced an anti-HIV immune system response and were found to be safe.
The human participants, from Thailand, South Africa, Uganda, and Rwanda, ranged in age from 18 to 50 years.
An accompanying editorial by George N. Pavlakis, MD, and Barbara K. Felber, PhD, both of the National Cancer Institute in Frederick, Maryland, discussed this approach, stating that it "defines an additional path for exploring the development of an effective HIV vaccine". They also note that there is no definitive immunological measurement that is known to predict protection against HIV-1 in humans.