An HIV vaccine is one step closer
Since its discovery in 1983, the human immunodeficiency virus (HIV) has infected more than 85 million people and caused approximately 40 million deaths worldwide.
Although the medicine known as pre-exposure prophylaxis, or PrEP, can significantly reduce the risk of contracting HIV, it must be taken every day to be effective. A vaccine that provides long-lasting protection has eluded researchers for decades. Now there may finally be a viable strategy to achieve this goal.
Girls, adolescents and women continue to be disproportionately affected by the HIV epidemic.
Broadly neutralizing antibodies for HIV vaccine
An experimental vaccine developed at Duke University in North Carolina produced an elusive type of broadly neutralizing antibody in a small group of people participating in a 2019 clinical trial. The results were published today in a scientific journal. cell.
“This is one of the most significant HIV vaccine studies to date,” says Glenda Gray, an expert on the virus and president and CEO of the South African Medical Research Council (South African Medical Research Council), who did not participate in the study.
Several years ago, a team from Scripps Research and the International AIDS Vaccine Initiative (IAVI) showed that it was possible to stimulate the progenitor cells needed to produce these rare antibodies in humans. Duke’s research goes one step further toward producing these antibodies, albeit at low levels.
“This is a scientific feat that gives great hope that we can develop an HIV vaccine regimen that targets the immune response in a way that is protective,” says Gray.
Vaccines train the immune system to recognize a virus or other pathogen. They inject something similar to the virus—such as a fragment or weakened version of it—and thereby prompt the body’s B cells to produce protective antibodies against it. These antibodies remain so that when a person later encounters the real virus, the immune system remembers it and prepares to attack.
While researchers were able to create a vaccine against Covid-19 in a matter of months, creating a vaccine against HIV proved much more difficult. The problem is the unique nature of the virus. HIV mutates quickly, meaning it quickly overcomes the body’s defenses. It also integrates into the human genome a few days after infection, hiding from the immune system.
“Some parts of the virus are similar to our own cells, and we don’t like to make antibodies against ourselves,” says Barton Haynes, director of the Human Vaccine Institute.Human Vaccine Institute) from Duke and one of the authors of the article.
The specific antibodies that researchers are interested in are known as broadly neutralizing antibodies, which recognize and block different versions of the virus. Due to the changing nature of HIV, there are two main types, each with multiple strains. An effective vaccine will need to target many of them.