More than sixty years ago, a new disease started spreading across the planet. It traveled slowly at first, quietly eating away at its hosts’ immune systems, and confounded the medical establishment for over two decades. It wasn’t until 1986 that this disease even had a name: Human Immunodeficiency Virus, or HIV.
More than 35 million people across the world now have HIV, and that number isn’t going down. But in the years since the medical community first discovered the disease, a lot of progress has been made: HIV is now treatable and even potentially curable. But the holy grail of HIV research has always been to find a vaccine.
As of this week, that dream might be a reality. As part of a Phase 1 clinical trial at the University of Oxford, the very first injections of a new HIV vaccine, known as HIVconsvX, have now been administered.
“An effective HIV vaccine has been elusive for 40 years,” explained lead researcher Tomáš Hanke. “This trial is the first in a series of evaluations of this novel vaccine strategy in both HIV-negative individuals for prevention and in people living with HIV for cure.”
What sets this vaccine apart from other candidates is how it works. Most other potential vaccines work by inducing the B-cells in our blood to release antibodies, Hanke explained. HIVconsvX, on the other hand, induces the T-cells: a type of white blood cell that can literally kill virus-infected or cancerous cells. The vaccine works by targeting these T-cells to the most vulnerable regions of the HIV virus – its “Achilles heel”, the researchers say.
The vaccine will initially be administered to thirteen healthy, HIV-negative volunteers with a low risk of infection, followed by a booster shot after four weeks. As a phase 1 trial, the researchers want to measure the vaccine’s safety, how well patients can tolerate any side effects, and of course how effective it is at triggering those T-cells.
Currently, the best protection from contracting HIV is mostly behavioral modifications: use condoms (yes, even if you’re both women – it’s rare, but not impossible to transmit through lesbian sex), don’t share needles, and in certain cases, get circumcised. Those who have been exposed to the virus can take post-exposure prophylaxis (PEP) medicine, which can stop the infection from taking hold, while a person who becomes HIV-positive will be prescribed antiretrovirals. These are drugs that stop the virus from replicating itself inside the body, keeping the viral load low and allowing the patient’s immune system a chance to repair itself. Antiretroviral therapy is actually so effective nowadays that it’s possible to get to a point where the virus is virtually undetectable.
‘There is strong evidence that undetectable HIV viral load prevents sexual transmission,” Hanke said. “Nevertheless, the pace of decline in new HIV infections failed to reach the Fast-Track Target agreed upon by the United Nations General Assembly in 2016: fewer than 500,000 new infections per year in 2020.”
“Even in the broader context of increasing antiretroviral treatment and prevention, an HIV-1 vaccine remains the best solution and likely a key component to any strategy ending the AIDS epidemic,” he said.