Scientists have chosen two “targets” for the immune system at once – the env protein, which forms the basis of the HIV envelope, as well as the gag protein, which plays the role of the internal framework of viral particles.

American molecular biologists have developed an experimental HIV vaccine based on matrix RNA and successfully tested it in experiments on mice and rhesus monkeys. This was announced on Thursday by the press service of the National Institute of Allergy and Infectious Diseases (NIAID).

“We have spent almost 40 years developing HIV vaccines, but so far this task has not been solved. The experimental RNA vaccine we have created has several features that favorably distinguish it from past attempts to create an immunodeficiency virus vaccine,” said Anthony Fauci, director of NIAID, whose words are quoted by the press service of the institute.

Like the RNA vaccines from COVID-19, this drug consists of special fat nanoparticles that contain a fragment of RNA encoding part of the proteins of the immunodeficiency virus. These nanostructures can penetrate human cells and cause them to produce a large number of fragments of the HIV protein envelope, which in theory leads to the formation of an immune response to the virus.

In this case, as Fauci notes, scientists have chosen two “targets” for the immune system at once – the env protein, which forms the basis of the HIV envelope, as well as the gag protein, which plays the role of the internal framework of viral particles. Their combination, as biologists have suggested, should reduce the likelihood that changes in the structure of the HIV envelope will make it invulnerable to the action of the vaccine.

New HIV vaccine

Guided by this idea, American researchers prepared RNA chains that force cells to synthesize both viral proteins and embedded them in fat particles that are as similar in size, shape, and other properties as possible to the real immunodeficiency virus. In addition, the scientists created an alternative version of the vaccine, which forced cells to produce only the env protein.

Scientists have tested the work of both forms of RNA vaccination against HIV in experiments on mice with a partially human immune system, as well as on ordinary rhesus monkeys. The introduction of the vaccine did not cause dangerous side effects in them and led to the formation of a large number of antibodies capable of combining with particles of the immunodeficiency virus.

Subsequent observations indicated that the vaccine attacking both viral proteins reduced the risk of HIV infection by about 79%, while the second vaccination caused an immune reaction much less often and did not protect animals from infection with the immunodeficiency virus. Repeated administration of the vaccine, as noted by Fauci and his colleagues, increased the level of protection against HIV and did not cause dangerous side effects.

According to biologists, they are developing new methods of manufacturing nanostructures, which will make them even more similar to HIV particles. This, scientists hope, will increase the effectiveness of the vaccine, which will reduce the number of injections needed to achieve immunity. In the coming years, Fauci and his colleagues plan to start testing a new version of this drug on healthy volunteers.