While COVID vaccines have appeared in a record-breaking short time, an HIV vaccine is still yet to arrive – though not without good reasons, as The Daily Maverick reports.
Mitchell Warren, executive director of AVAC, a US-based HIV advocacy organisation explained: “There is still no conclusive research on what type of immune response an HIV vaccine should be trying to trigger.”
“With HIV, you’re trying to do better than nature,” continued Warren. “With a Covid-19 vaccine, the jab merely has to do what nature is doing already — in the form of an immune response — just faster. But with HIV, you’re trying to do better than nature because your body isn’t able to successfully fight off the virus.”
HIV mutates quite rapidly, to the point where there are now two distinct strains, HIV-1 and HIV-1, complicating the process. SARS-CoV-2 on the other hand uses a process called proofreading when it replicates, ensuring a lower rate of mutations.
There are currently three vaccines in development; HPX2008/HVTN 705: Imbokodo and HPX3002/HVTN 706: Mosaico both use adenoviruses to deliver protein fragments of the HIV virus to train the immune system to respond to it. The “Imbokodo” is being trialled with young women, and “Mosaico” is being trialled with transgender men and men who have sex with men, and expected to end in 2022 and 2024 respectively.
The PrEPVacc vaccine uses DNA inserted into plasmids, which induce the body to produce the virus’ proteins, but not the virus itself. The two shots contain a cocktail of proteins and the plasmids to train the immune system. The trial is expected to end in 2023
