Researchers from the National Institutes of Health’s (NIH) National Institute of Allergy and Infectious Diseases (NIAID) conducted a year-long clinical trial to make the body create a specific antibody against HIV. The study used a virus to deliver an antibody, which would then allow the body to create the antibody itself over time. The researchers believe that this same strategy could be used to prevent many infectious diseases. The researchers presented their work orally at the 2020 Conference on Retroviruses and Opportunistic Infections (CROI).
Antibodies are blood proteins that the body produces in response to an antigen; antibodies can help the body fight infection or prevent the infection, and this is how vaccines work. But there’s another approach to fighting disease by using monoclonal antibodies. These antibodies are already being used to treat cancer and various autoimmune diseases. Scientists are trying to determine if monoclonal antibodies can help fight infectious diseases like Ebola.
According to NIAID Director, Anthony S. Fauci, M.D., “Monoclonal antibodies hold enormous promise for preventing and treating both established and emerging infectious diseases. Novel delivery platforms such as viral vectors could facilitate the future development and deployment of antibody-based prophylaxis and therapy, and these findings are a promising first step in that direction.”
The NIH study used the adeno-associated virus serotype 8 (AAV8) to deliver an anti-HIV antibody gene to 30-60-year-old adults whose HIV was well controlled. The vector (or virus) that the researchers used carried the gene for an anti-HIV monoclonal antibody called VRC07. The study participants all had some increase in AAV8-VRC07. The first eight participants received an injection of AAV8-VRC07. Five participants got low or intermediate doses and were monitored for up to two years. Three of these five people showed higher antibody levels than they did 4-6 weeks post-injection. The other three participants received a higher dose of AAV8-VRC07 and were monitored for up to one year. Two of these three people produced VRC07 n higher concentrations than the participants who received lower doses.
According to NIAID Vaccine Research Center Director, Dr. John Mascola, “To the best of our knowledge, this marks the first time that an AAV-based technology to deliver an antibody gene has resulted in safe and sustained levels of that antibody in blood. We hope that further development of this technology will yield a drug-delivery strategy applicable to a broad range of infectious diseases.”