A promising HIV vaccine has just emerged. In a new study, scientists share an experimental vaccine and its success in human and rhesus monkey trials.

For years, the medical community has been trying to find an effective way to ward off the virus. Now, researchers from Harvard University may have found the answer.

An Experimental Vaccine Shows Positive Results

The study, published in The Lancet, reveals that an experimental vaccine for HIV-1 produced comparable and robust immune responses in both humans and rhesus monkeys. It was also able to protect monkeys from an infection with an HIV-like virus.

Human trials included 393 participants in 12 clinics all over the world. All of them were aged 18 to 50 with healthy medical records and no HIV. The participants received four vaccinations over 48 weeks, all of which were found safe and able to produce the anti-HIV response, according to Interesting Engineering.

Seventy-two rhesus monkeys were also part of the trials.

"These results represent an important milestone," coauthor Dan Barouch says in a statement. "This study demonstrates that the mosaic Ad26 prime, Ad26 plus gp140 boost HIV vaccine candidate induced robust immune responses in humans and monkeys with comparable magnitude, kinetics, phenotype, and durability and also provided 67 percent protection against viral challenge in monkeys."

Barouch is the director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center as well as a professor of medicine at the Harvard Medical School.

So far, this is one of only five experimental HIV-1 vaccines that was able to reach this trial stage.

Researchers Remain Cautious

Despite the relatively good results from the human and animal trials, the researchers are careful not to be too confident in the potential vaccine.

Barouch says even these results should be taken with a bit of caution.

"The challenges in the development of an HIV vaccine are unprecedented, and the ability to induce HIV-specific immune responses does not necessarily indicate that a vaccine will protect humans from HIV infection," he explains.

At this point, Barouch says, the team is eager to see the results of the next phase of trials, "which will determine whether or not this vaccine will protect humans against acquiring HIV."

Vaccine Against HIV Is Critical

Finding a vaccine to fight HIV is considered a priority by health agencies worldwide. After all, a huge chunk of the global population is afflicted with it, and the number continues to grow.

Roughly 37 million people live with HIV or AIDS, and there are 1.8 million new cases every year.

As BBC points out, the drug Prep can prevent the infection, but it needs to be taken regularly — as often as daily — to avoid the disease. Scientists have been continually working toward a vaccine, but it's extremely challenging due to the number of various strains there are.

This new "mosaic" vaccine is still in its early stages, but if it passes the different trials, it will go a long way in offering protection to people around the world.