This week, the US National Institutes of Health will launch a trial of three HIV vaccines in 108 healthy adults. This is a phase I clinical trial, and the vaccines they use are all mRNA vaccines, developed by Moderna Pharmaceuticals.
mRNA vaccine technology has proven its power during the COVID-19 pandemic. It works on the principle of turning every cell in the body into a vaccine factory.
To do this, scientists must engineer mRNA molecules that encode viral proteins. In the case of the SARS-CoV-2 virus, it is the spike proteins on the outside of its shell.
When injected into the body, the mRNA molecules instruct our cells to produce these spike proteins. The immune system then learns to recognize those proteins. So that when the real SARS-CoV-2 virus enters the body, our immune cells and antibodies will destroy them.
Moderna used the same principle to develop its three HIV vaccine candidates. The mRNA vaccine for HIV encodes the proteins of the HIV virus.
But HIV has a reputation as a crafty virus. It has many tricks to evade the immune system and stay in our body. HIV has the ability to change parts of its structure so quickly that antibodies that were previously specific to the virus will sooner or later no longer recognize them.
Unlike the spike protein on the outside of the SARS-CoV-2 virus that rarely mutates, the spikes on the outside of the HIV virus mutate continuously and produce new HIV variants. Right now, there are about 50 million different HIV virus variants in the world. This has brought all efforts to develop a vaccine against HIV so far to a standstill.
The opportunity opened up only after some scientists observed that particular individuals were able to produce antibodies that responded broadly to multiple strains of HIV at the same time. These antibodies target the stable part of the virus, where HIV rarely mutates. It is this that helps the antibody to remain effective even if the virus changes.
Moderna is developing these injections in collaboration with scientists from the Scripps Consortium for HIV/AIDS Vaccine Development, the Scripps Research Institute, and the IAVI Neutralizing Antibodies Center funded by the Bill & Melinda Gates Foundation. aid.
Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, said: “Finding an HIV vaccine is a daunting scientific challenge. But after the success of the COVID-19 vaccine, [cho thấy mRNA] Given the high safety and efficacy, we had the opportunity to find out if mRNA technology could achieve the same results, against HIV infection?”
That opportunity is being placed on 108 volunteers participating in the trial. They were carefully selected, in good health and between the ages of 18-55.
Volunteers will be divided into two groups. The first group injected a low dose, to assess the safety. If after 2 weeks the vaccine did not cause serious side effects, a second group joined the injection with a higher dose.
Monitoring continues and if all goes well, volunteers will receive two more doses, 2 and 6 months later. The trial is expected to end in July 2023.
Because this is only a phase I clinical trial, scientists are mainly evaluating the safety of the vaccine. They cannot yet say whether the vaccine is effective against the HIV virus.
But some data from this trial still provides clues to evaluate that potential, preparing for the next phases of phase II and phase III clinical trials.
Normally, the development of vaccines like this would take several years. If all goes well, we should have an anti-HIV mRNA vaccine by 2026.
Refer to Gizmodo