The dream of an effective and safe HIV vaccine has been temporarily put on hold following the announcement that the Mosaic study will be discontinued. In human tests, the immunizing potential against the AIDS virus was developed by Janssen — the pharmaceutical arm of Johnson & Johnson. According to analyses, the formula did not obtain the expected effectiveness.
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Initiated in 2019, the Phase 3 clinical trial was officially known as HPX3002/HVTN 706. In total, the Mosaico research involved around 3,900 volunteers, aged between 18 and 60 years, spread across numerous countries, such as Brazil — FreeGameGuide even interviewed the scientists responsible for the research.
At this time, HIV vaccine study participants are notified of the early termination of testing. During testing, safety issues were not highlighted, such as serious adverse effects.
Discontinued due to lack of effectiveness
The decision to discontinue the trial for an HIV vaccine was made following a report from the Independent Data and Safety Monitoring Panel (DSMB). Reviewing the research data, the group identified that the number of HIV infections was equivalent between people who received the vaccine and the placebo. However, no security-related issues were identified.
It is worth explaining that, to immunize, the formula contained fragments of a wide variety of HIV strains — hence the name Mosaico. To deliver this information, the vaccine used a genetically-edited common cold virus (Ad26). Despite the concept, the immunizer failed to obtain the necessary effectiveness for the studies to continue and the formula to reach the market.
Why is it so difficult to create a vaccine against the AIDS virus?
“Science is like that”, comments the doctor and infectologist Vinícius Borges, on social networks, about the outcome. “We don’t always get the result we want, but the knowledge accumulates,” he adds of the findings provided by the tests.
“Developing a vaccine against HIV is extremely challenging”, explains the doctor. Even different options considered promising have failed to demonstrate efficacy during clinical studies. This is because, according to Borges, “the virus is extremely mutable, it hides and manages to escape the immune system”.
Today, to prevent new HIV infections that occur through sex, there are three main ways: the use of condoms during intercourse, Pre-Exposure Prophylaxis (PrEP) and Post-Exposure Prophylaxis (PEP). It should also be noted that people who live with the virus and treat the infection continuously — they are undetectable — do not transmit the infectious agent.
In the future, it is possible that a long-awaited vaccine will join this range of preventive options, since other research is still in progress. This is the case with Moderna’s mRNA (messenger RNA) formula.