Following the success of two of the COVID-19 vaccines in clinical trials this past year, researchers are working to take a similar approach to HIV.
Last year, the pharmaceutical companies Pfizer and Moderna developed and tested vaccines for the COVID-19 virus that are part of an entirely new class of vaccines, which could open up new possibilities for fighting infectious diseases. And a small trial on monkeys is already showing promise for an HIV vaccine.
Related: Here’s why COVID-19 has a vaccine after 1 year and HIV doesn’t after nearly 40 years
Traditional vaccines are usually made from inactivated or weakened microorganisms, or fragments of microorganisms, or molecules produced by those microorganisms.
When injected into a person, the immune system develops a response to a virus or bacterium without actually being exposed to an active and harmful version of the disease. The body remembers that immune response for the next time it encounters the disease and is able to fight it before it has a chance to copy itself or multiply.
The COVID-19 vaccines developed by Pfizer and Moderna, though, take a different approach. They’re made from mRNA, which is a molecule found in all living things that codes for proteins. It stores information in a chemical structure, much like DNA does.
When the mRNA that codes for a certain COVID-19 protein enters a person’s cells, it can produce copies of the protein and the immune system can learn how to capture and destroy that protein. That way, when a person is exposed to the real virus, it’s ready to destroy it before it can make copies of itself.
The thing is, people can’t just be injected with mRNA and then they’re immune to the virus. mRNA is fragile and has a hard time entering cells, but pharmaceutical researchers have been working for decades to overcome those obstacles. The Pfizer and Moderna vaccines show that they found a decent way of doing so – each of them is effective around 95% of the time.
“The uniquely challenging year of 2020 for all of society proved to be an extraordinary proof-of-concept period for Moderna,” Moderna CEO Stéphane Bancel said in a statement. “Even as we have shown that our mRNA-based vaccine can prevent COVID-19, this has encouraged us to pursue more-ambitious development programs within our prophylactic vaccines modality.”
Scientists are already working on ways to apply this same technique to other diseases, including the flu, Nipah virus, and HIV.
While the virus that can lead to AIDS has been around for decades, a vaccine hasn’t been developed for it because it mutates quickly, there are a lot of different strains, and HIV has the ability to remain latent for long periods of time. Put another way: vaccines trigger an immune reaction similar to getting a disease and recovering naturally from it. But almost no one has ever recovered from HIV.
POZ describes a study that Moderna is working on for an mRNA vaccine for HIV, which could change things. Sixteen monkeys were given a trial version of a vaccine for three different strains of HIV and then injected with a human-simian hybrid version of HIV. The trial showed that the vaccine provided “significant protection” from the virus.
In a statement, Moderna said that they’re expecting to start phase 1 of a clinical trial for the vaccine in humans this year.
Another trial for a different vaccine at the University of Pennsylvania on humanized mice also showed promise.
In 2016, Anthony Fauci of the National Institute of Allergy and Infectious Diseases said that even a moderately effective vaccine would be “the final nail in the coffin for HIV” if used alongside other tools for HIV prevention.