A newly launched HIV vaccine trial will test a unique approach to protecting people from the virus — and it might even lead to a cure for people who are already infected.
The challenge: Most vaccines work by introducing the immune system to a harmless bit of the pathogen. This prompts the immune system to create antibodies that will quickly recognize and neutralize it if we ever encounter it in the wild, preventing an infection from taking hold.
HIV has proven incredibly difficult to vaccinate against, though, because (among other reasons) the virus mutates frequently. There are many strains of HIV, and the vaccine-produced antibodies need to work against all or most of them.
The idea: The Oxford team has developed an HIV vaccine (HIVconsvX) that takes a different approach, prompting the creation of another immune system weapon — T cells — and training those cells to target a vulnerable part of the virus that doesn’t mutate often.
“Achieving protection against HIV is extremely challenging, and it is important that we harness the protective potential of both the antibody and T cell arms of the immune system,” Paola Cicconi, chief investigator of the HIV vaccine trial, said in a press release.
Why it matters: Thanks to the development of antiretroviral therapy (ART), a person with HIV today can expect to live just as long as an uninfected person — with proper treatment. People without the virus, meanwhile, can take a medicine called PrEP to dramatically lower their risk of contracting it.
“A vaccine is likely a key component to any strategy ending the AIDS epidemic.”
Tomáš Hanke
However, both ART and PrEP meds usually have to be taken every day, and the cost of that can add up. In very poor places, disproportionately affected by HIV, consistent treatment is difficult to get. An effective HIV vaccine might be able to offer much longer-lasting protection with a single shot.
“Even in the broader context of increasing anti-retroviral treatment and prevention, an HIV-1 vaccine remains the best solution and likely a key component to any strategy ending the [AIDS] epidemic,” Tomáš Hanke, lead researcher of the HIV vaccine trial, said.
The HIV vaccine trial: Oxford has enrolled 13 adults under the age of 65 in its phase 1 trial. All of the participants are healthy, HIV-negative, and considered at low-risk of contracting the virus.
Each will receive one dose of the vaccine, followed by a booster dose four weeks later. The researchers will study the safety of the vaccine, how well participants tolerate the shot, and what sort of immune response it prompts.
They plan to launch similar trials in Europe, Africa, and the United States as well.
Looking ahead: Results from this phase 1 HIV vaccine trial could be ready by April 2022. If positive, the shot’s ability to actually prevent infection would be put to the test in future trials.
The researchers also plan to test the shot’s potential use as a therapeutic vaccine — meaning this one vaccine might not only be able to protect HIV-negative people from the virus, but also cure those who’ve already been infected.
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