Researchers have been working to find an HIV vaccine for over 30 years. Most vaccines, like the vaccines for measles and chickenpox, work by triggering the body’s immune system to produce antibodies. These antibodies are usually sufficient to prevent future infections. However, due to the way HIV replicates itself and mutates inside the body, antibodies are unable to clear an HIV infection.
Over the years, different approaches have been tested for a possible vaccine. For many years, vaccine trials reported no reduced risk of infection, but in 2009, the RV144 trial reported a 31% reduced risk of infection. This study combined two vaccines that were not effective on their own. Results of this study have been widely discussed and raised hopes that an HIV vaccine may become available in the near future.
Two major vaccine trials called Mosaico and Imbokodo, which use similar vaccine regimens with RV144, are expected to publish results from their next phases by 2023. The researchers hope that these vaccines will be more effective than the ones used in RV144. However, another large trial using a similar vaccine regimen was stopped early in February 2020 when it became clear that the vaccine did not work.
Current developments in the vaccine research have shown it is possible to find a vaccine. Still, even if we find an effective vaccine today, there are regulatory processes to ensure the safety and efficacy of the vaccine for everyone. Considering the time still needed for further research and regulatory approvals, it will take at least five years before a vaccine is available worldwide.