Moderna is testing an mRNA vaccine against HIV in humans

Moderna’s experimental HIV vaccine is already being tested in humans, according to a new submission to the US National Institutes of Health clinical trial registry.

The trial of the first phase of testing will include 56 healthy adults aged 18-50 years who are not HIV positive and will test the safety of the vaccine and will also be tested for basal immune responses. Moderna’s HIV vaccine candidate is functionally similar to the mRNA system that was effective with Moderna’s COVID-19 vaccine.

Scientists have been studying the potential of mRNA vaccines for years, but the Pfizer and Moderna vaccines against COVID-19 are the first to be used in humans and both have been shown to be safe and widely effective in preventing and reducing the severity of SARS-CoV-2 infection.

Moderna will test two versions of its new vaccine candidate, officially named mRNA-1644 (the variant is known as mRNA-1644v2-Core). It is the first mRNA vaccine against HIV to be tested in humans.

The study will test four groups – two will receive a mix of vaccine versions and two will receive one or the other.

Early on, the test is not ‘blind’, meaning anyone who receives the vaccine will know what they’re getting. That’s because at the moment scientists aren’t trying to figure out how well the vaccine works. This first phase will take about 10 months for scientists to make sure it is safe and that it triggers an underlying immune response.

If the vaccine passes this phase, it will still have to go through Phase 2 and Phase 3 trials to determine how effectively they are preventing HIV infection in the wider population.

I wrote about how mRNA vaccines work in my recent post based on the Focus monthly diagram. But I would like to remind you that unlike traditional vaccines, which usually contain some part of a weakened or inactivated virus, mRNA vaccines contain a protein with “instructions written” that is passed to our cells and tells them how to make fragments of specific proteins that are outside target virus.

For a short period (usually 24 to 48 hours) our cells begin to produce these proteins and our bodies mark them as foreign and trigger an immune response. Hopefully, when you are exposed to the virus, your body will recognize the protein spikes and be quick enough to fight them off before the infection becomes too serious.

According to the conclusion of the Moderna clinical trial on an HIV vaccine candidate: “The hypothesis is that sequential vaccination with a germline-targeted first dose followed by a targeted boost of immunogens may induce and target specific classes of B-cell responses. early maturation towards neutralizing antibodies (bnAb) development through the mRNA platform. ” It’s a bit overkill, but stimulating these broadly neutralizing antibodies (bnAbs) is important when it comes to HIV.

We are already very good at using antiviral drugs to treat HIV and reduce the risk of infection in an exposed person. However, creating a vaccine against the virus has proven difficult because of how quickly it infects our DNA and it is able to easily mutate its structure.

The most promising approach we have is to stimulate those broadly neutralizing antibodies that some people naturally develop against HIV – but which we have not been able to elicit with a vaccine so far. However, the mRNA approach may be different. Earlier this year, a study by the International AIDS Vaccine Initiative and Scripps Research tested the mRNA vaccine candidate component, the immunogen, but using a system other than mRNA. While a vaccine candidate did not achieve the full immune response they needed, 97 percent of participants developed the desired immune response – early B-cell stimulation.

The same immunogen was now used in a new study in conjunction with the Moderna mRNA system that was so useful against SARS-CoV-2.

The hope is that the combination will result in a wide range of neutralizing antibodies that are primarily able to fight HIV infection, and in the future may also be effective against a number of other viruses that may cause a “next pandemic”. The new process is being conducted in cooperation with the Bill and Melinda Gates Foundation.

In the April announcement addressed to shareholders, Moderna announced that apart from mRNA-1644 is also developing another HIV vaccine candidate, called as mRNA-1574. MRNA vaccines are also being studied to prevent many other viruses, such as the herpes simplex and influenza virus.

While the COVID-19 pandemic continues to rage around the world, it is promising that some of the technologies we have developed to fight it could also help us prevent other devastating viruses in the future.

You can read more about the Moderna Phase 1 trial here.

source: Moderna | Science Alert