For the past decade, even as researchers have developed more and more treatments that allow people with HIV to live longer and healthier lives, and early treatment and safe sex campaigns have slowed the spread of the virus, there’s been no means of actually preventing HIV infection. A snag in manufacturing has been holding up clinical trials for several different, promising HIV vaccines. But now, a breakthrough in vaccine production will allow these tests to go forward — which means an actual HIV vaccine is on the horizon.

Currently, 2.1 million people in India are thought to be living with the virus, and while the spread of infection has slowed significantly in the past decade, there were still 80,000 new infections in 2016; globally, 1.8 million new HIV cases were recorded in the same year. A vaccine would effectively bring down those numbers to nearly zero.

The stumbling block has been the technical difficulty of manufacturing vaccines based on the envelope proteins of the virus, according to Phil Berman, a biomolecular engineer who led development of a major component of the only vaccine to have shown any efficacy against HIV in a clinical trial so far. Envelope proteins are found on the surface of viruses; they allow viruses to identify and bind to host cells — in other words, infect.

Berman has now developed new methods for the production of HIV vaccines based on envelope proteins.

“Dozens of interesting vaccine candidates have been described, but most have not been tested in humans because it has not previously been possible to manufacture them affordably and in a timely fashion,” Berman said. “The technology we developed should break the logjam in HIV vaccine development, because it tremendously shortens the time, improves the yield, and lowers the cost.”

Berman’s lab was able to use robotics to shorten the time required to produce the stable cell lines needed to make the proteins for a vaccine, while at the same time greatly increasing how much of the protein the cell lines can produce. The improved yield makes it possible to reduce the size of the bioreactor needed to make vaccine for large clinical trials — from 2,000- to 10,000-liter vessels to 50- or 100-liter vessels — resulting in tremendous savings in the equipment required and cost of materials.

In addition, Berman’s lab was able to create cell lines that make HIV envelope proteins with the right kind of carbohydrate components (called glycans) needed for an effective immune response.

“The carbohydrates attached to the protein are really important, something no one realized until recently,” Berman said. “The conventional way of making these envelope protein vaccines incorporated the wrong kind of carbohydrates.”

The breakthrough comes right as estimates of the power of future vaccines have been making the news. In a recent study published in Health Affairs, Angela Chang, of Harvard University, and a team of researchers project that as many as 36 million deaths and 24 million cases of medical impoverishment across 41 low- and middle-income countries (including India) would be averted by vaccines over the next 12 years. The authors looked at vaccines that prevent ten diseases, including measles, hepatitis B, and yellow fever, and not including HIV/AIDS. With this latest breakthrough in vaccine production, hopefully the number of lives and livelihoods saved might reach even higher.