They represent new advances in creating an effective HIV vaccine through a consistent strategy | Health | Magazine

Scientists have made several advances in developing a class of HIV vaccines that could provide broad protection against the virus.according to four new research papers that have developed different methods for producing broad-spectrum neutralizing antibodies.

The results of these still preliminary studies are published in journals. The science, Scientific translational medicine And Science Immunologyand all four describe new steps in the sequential vaccination strategy to obtain effective candidate against HIV virus.

Experiments have been conducted on rhesus monkeys and mice, and one of the proposals is in phase 1 clinical trials. The authors include scientists from the Scripps Research Institute of America, the University of Louisville and the University of California at San Diego.

The HIV epidemic has entered its fifth decade, and the scientific community has devoted time and resources to developing potential vaccines against the virus.

However, health authorities still lack an effective and approved vaccine against broadly neutralizing antibodiescapable of neutralizing the most common circulating strains of HIV, recalls the team’s summary The science.

One solution is a process called germline selection, in which researchers use a series of immune-targeted proteins (immunogens) to guide and “court” young B cells as they mature at sites called germinal centers.

The goal is to induce cells to produce broadly neutralizing antibodies against HIV.

José Alcamy, director of the AIDS Immunopathology Unit at the Carlos III Health Institute, notes that the goal of any prophylactic vaccine is to induce the production of neutralizing antibodies by the immune system, and the antigen typically used must include or be produced by the envelope. or surface proteins of the virus.

It is these proteins that interact with cell entry receptors, so their blockade by antibodies neutralizes the viral infection.

points to Science Media Center Spain (SMC), a science resource platform.

The difficulty of obtaining a vaccine is created by the structure of the HIV shell, which makes it very inaccessible to the action of neutralizing antibodies, says a virologist not involved in the research.

Given the difficulty of producing neutralizing antibodies against HIV, the authors of the new works direct the immune system to produce a specific type of neutralizing antibodies with various immunogens.

“First simpler (so that they can be better recognized) and then more complex and closer to the original HIV envelope protein,” details Julia Blanco, head of the virology and cellular immunology group at the IrsiCaixa AIDS Research Institute.

The HIV envelope protein has different regions that are recognized by neutralizing antibodies. For a specific region(CD4 binding site), this strategy has already been used and has even reached human studies.

Now a second region appears (loop base v3), which can also be used in a similar way. “By combining both strategies, it would be possible to create a greater number and variety of these neutralizing antibodies (making the potential vaccine more effective),” explains Blanco, who is not involved in the research.

Sequential vaccination can be an excellent strategy, but it may require excessive amounts of immunogens, making it difficult to convert into a product that reaches the population most in need. “There is a lot of work ahead,” he sums up SMC. (HEY)