So, Is There an HIV Cure?
HIV was first identified forty years ago, and since then, the medical community has made significant progress with testing, treatment, and developing a vaccine and a cure. While there is no cure or vaccine yet, researchers have recently made excellent headway using gene therapy and other avenues.
Different Pathways to a Cure
Researchers and scientists believe that the world will find a cure for HIV, but there are different pathways for a cure.
A functional cure can reduce HIV in the body to levels that it can’t be detected or make someone sick, but it does not completely get rid of the virus from a body. While some may consider the current treatments (ART, or antiretroviral treatment) as a functional cure, ideally, a functional cure would suppress the virus without the need to take drugs for the rest of an infected person’s life.
A sterilising cure, however, would eradicate the virus from the body. This cure would include removing HIV from hidden reservoirs in the body – that is, from cells infected with HIV in the early stages but are not actively producing HIV in the body.
There are no vaccines for HIV yet, but research is continuing to develop one. One set of research that is ongoing is through Duke University’s Human Vaccine Institute. Derek Cain’s team has focused on a subset of HIV patients (fewer than one-third) who eventually develop specialized antibodies that can neutralize HIV after infection. If a vaccine can induce these antibodies, there is hope that they could destroy HIV before it can take hold in an infected person.
While COVID-19 has had a negative impact on the world, there is some good news to come out of the ongoing pandemic. Based on the molecule that instructs our cells to make specific proteins, the mRNA COVID-19 vaccine has shown the possibilities of this technology, previously viewed with some skepticism about its effectiveness. The successful roll-out of COVID vaccines opened up the possibility of using this technology for other diseases such as HIV. However, it is still acknowledged that an HIV vaccine will be complicated due to the nature of the virus itself, which becomes part of the human genome 72 hours after transmission.
With the recent news that Moderna will start human trials for its mRNA HIV vaccine, it appears the fight to end HIV as a global endemic and public health crisis has received a boost. The mRNA vaccine is intended to prime B cells that have the potential to produce highly potent neutralizing antibodies by working to target the virus’s envelope to keep the virus from entering and infecting cells. The envelope is the virus’s outermost layer that acts as protection for its genetic material. The trials will test the safety of the different experimental vaccines.
HIV Cure Research Approaches
There are a few different approaches to research cures. While each is promising, as of yet, there is no cure.
- Activate and eradicate – aims to flush the virus out of the reservoirs and kill any cell it infects – this is sometimes known as “shock and kill”
- Gene editing – this is about changing cells so that HIV cannot infect cells in the body
- Immune modulation – this method permanently changes the immune system to better fight against HIV
- Stem cell transplants – this approach replaces a person’s infected immune system with a donor immune system
There Have Been Two Cases of People Cured of HIV
There are two cases where researchers cured HIV entirely, both as part of the sterilising approach.
The first in was Timothy Brown (also known as the Berlin Patient), who received chemotherapy and a bone marrow transplant as part of his leukemia treatment in 2007. The transplant was from a donor who had a natural resistance to HIV, and following Brown’s transplant, he appeared to be free of HIV.
Following this, doctors replicated this result on another patient, Adam Castillejo, or the London Patient, where following his transplant, became HIV-free. As of 2020, 30 months after stopping treatment, Adam was still HIV-free.
Does This All Mean We Will See an HIV Cure in 2021?
Well, this September, the FDA approved the first human trial investigating CRISPR gene editing as an HIV cure. And while this doesn’t mean we will see a cure immediately, this showcases the progress researchers and scientists have made towards ending HIV as a global health threat.
Excision BioTherapeutics will begin trials, a first-in-human Phase I/II trial, to evaluate the safety, tolerability, and efficacy of EBT-101 as a potential functional cure in healthy individuals living with HIV. EBT-101 uses CRISPR to excise HIV wrapped around DNA in cells, which has been challenging to treat and is primarily why past curative efforts have not succeeded. Harnessing adeno-associated virus (AAV) at a relatively low rate, this therapy uses one dose to deliver treatment.
It is great to see that both a vaccine and a cure are possible and even likely in our futures with these advancements.