Scientists just hit a new milestone for testing their HIV vaccine

The HIV/AIDS crisis in the United States isn’t exactly over. Thousands of people are still contracting HIV every year in the U.S. — an estimated 38,500 people became infected with the virus in 2015 alone, according to the Centers for Disease Control and Prevention’s latest statistics. Worldwide, that number is even more daunting: About 1.8 million people are thought to have been infected in 2016.

And although we now live in the era of PrEP — a highly effective, preventative drug — its high price tag makes it out of reach for many of the millions affected. Before insurance, a 30-day supply can be as much as $2,000, NPR reported, and some Americans are still being denied coverage.

Now, scientists are making significant strides toward an alternative solution: HIV vaccines. A new study published in the Lancet reveals that scientists have tested the vaccine on humans and rhesus monkeys, and they plan to administer it to a group of 2,600 women at risk for HIV in southern Africa next.

This further phase of testing — called a “2b trial” — will hopefully bring promising results.

“These results represent an important milestone,” Dan Barouch, director of the Center for Virology and Vaccine Research at the Beth Israel Deaconess Medical Center, said in a release.

The formula Barouch and his colleagues are working on is one of five vaccine candidates to have ever made it to this stage of testing.

Over the course of 48 weeks, researchers administered one of seven combinations of the vaccine (or a placebo) to a group of 393 adults without HIV. The adults came from clinics across East Africa, South Africa, the U.S. and Thailand.

They found that “all vaccine regimens tested were capable of generating anti-HIV immune responses in healthy individuals,” meaning that the study participants built up some kind of protection from the virus.

With that said, it doesn’t necessarily mean that the patients are incapable of contracting HIV — and it would be unethical to try to infect them with the virus to find out. Though the results are no doubt exciting, the truth is that scientists are still far from a finished product.

“These results should be interpreted cautiously,” Barouch said. “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.”

For now, it’s a waiting game. But perhaps one day, one of the world’s deadliest viruses can finally be a thing of the past.