Moderna's HIV Vaccine to Start Human Trials Early As Wednesday, Uses mRNA Like COVID Shot

Biotechnology company Moderna is preparing to begin human trials on HIV vaccines as early as Wednesday, using the same mRNA platform as the firm's COVID-19 vaccine.

An entry posted Wednesday to the National Institutes of Health's registry of clinical trials shows that the trials are estimated to start on August 19 and should be completed by spring 2023.

Moderna has two HIV vaccine candidates, mRNA-1644 and mRNA-1644v2-Core, both of which have cleared initial safety testing before being used on humans for the first time. The randomized trials will include 56 HIV-negative participants aged 18 to 56.

HIV is one of several viruses that Moderna is targeting for vaccine development using the mRNA platform. The Moderna and the Pfizer/BioNTech COVID-19 vaccines were the first-ever mRNA vaccines authorized for human use in the U.S., although the technology had been in development for decades and was reaching maturity as the pandemic emerged.

Attempts to develop an HIV vaccine have been ongoing for decades but have met with little success. While multiple vaccine candidates have reached the trial stage, not all were found to be safe and almost none were shown to be even modestly effective.

Moderna mRNA Vaccine HIV COVID-19 Clinical Trials
Moderna's HIV vaccine candidate, which uses the same mRNA technology as the company's COVID-19 vaccine, is expected to begin clinical trials as soon as next week. This undated file photo shows a hand guiding the injection of an unknown substance into a model of a virus. Andrey Rykov/Getty

What was likely the most effective candidate, a vaccine trialed in Thailand during the 2000s, was found to reduce infections by around 30 percent, although the trial results were considered controversial by some scientists.

Scientists were forced to call off the trial of a different vaccine candidate during the same decade when it was found that the vaccine may have actually increased the risk of catching HIV rather than preventing infections.

Unlike the Moderna candidate, none of the previous HIV vaccine candidates were developed using mRNA. Since the mRNA platform offers a fresh approach and has been shown to be safe and effective with COVID-19, scientists are hopeful that it will lead to an HIV breakthrough.

In addition, mRNA technology could have some distinct advantages over more traditional methods due to the nature of HIV—a virus that has quickly mutated into many different variants over the decades.

"The mRNA platform makes it easy to develop vaccines against variants because it just requires an update to the coding sequences in the mRNA that code for the variant," Dr. Rajesh Gandhi, an infectious disease expert who chairs the HIV Medicine Association, told Verywell Health.

"Based on its success in protecting against COVID-19, I am hopeful that mRNA technology will revolutionize our ability to develop vaccines against other pathogens, like HIV and influenza," added Gandhi.

Several other companies are also working on HIV vaccines. Some candidates are currently in, or about to enter, clinical trials. The other vaccines were developed using a variety of approaches, including the technique used in the partially-successful Thailand trial.

Newsweek reached out to Moderna for comment.