By Moderna and Pfizer made history in 2020 when they developed the world’s first vaccines for COVID-19 using what’s known as messenger mRNA technology. This marks the first time scientists have used this technology in the vaccination process, and it’s changing the way we look at infectious disease and other types of chronic health conditions.
Unlike other vaccines that infect the patient with a sample of the target virus, mRNA vaccines create a set of instructions on how to build specific proteins that trigger the body’s natural defenses. The instructions are temporary and do not affect the person’s actual DNA, which makes them much safer than other types of vaccines. This technology could be used to treat everything from cancer to addiction.
Based on the success of these vaccines, Moderna has just announced that it will use the mRNA method to create three new vaccines for 2021, including one for HIV.
The History of mRNA
Messenger mRNA technology is considered a potential game-changer in the field of medicine. Nucleic acid vaccines, which include plasmid DNA vaccines and mRNA vaccines, use genetic material to encode antigenic proteins in a person’s DNA. When administering the drug, the genetic payload enters the cytosol, or liquid matrix, of human cells. The cellular machinery then creates the antigenic proteins to elicit an immunological response.
There are many benefits to messenger mRNA vaccines. They are typically much faster and easier to produce than other types of vaccines. The encoded proteins do not remain in the human body long, which reduces any health risks associated with the drug. The body also amplifies the genetic material, so it can fight off infection even with small amounts of the expressed antigenic protein.
This technology was first discovered in the 1990s, but scientists were less than enthusiastic. They preferred plasmid DNA vaccines for their stability and effectiveness. Originally, mRNA vaccines were seen as too unstable. One major problem was that the proteins degraded rapidly in the body, making it harder to develop an immunological response. The other problem was that mRNA was considered an immunologically active molecule, and introducing it to a person’s immune system could lead to excessive immunization and inflammation.
Things changed in the mid-2000s when Hungarian biochemist Katalin Karikó, Ph.D. proved that mRNA vaccines could be just as effective as plasmid DNA vaccines at the University of Pennsylvania, debunking previous misconceptions.
Today, she’s the senior vice president at BioNTech, the German company that partnered with Pfizer to produce the world’s first messenger mRNA vaccine.
Targeting HIV and Other Infectious Disease
Now that mRNA vaccines have shown to be effective, Moderna is moving onto three new projects. The company recently announced it’s launching development programs for three new potential vaccines, including those for HIV, the seasonal flu, and the Nipah virus.
For the seasonal flu, the company says it hopes to make a combinatory vaccine that could be used to prevent seasonal illness as well as SARS-CoV-2, the virus that leads to COVID-19. That would make getting your yearly flu shot much easier. This would also give us the ability to protect ourselves against the coronavirus even as it continues to evolve.
Creating a vaccine for HIV will be more of a challenge. Dr. Anthony Fauci of the National Institute of Infectious Disease was recently asked whether he believes the messenger mRNA formula could be used to one day defeat HIV. He noted the clear differences between fighting COVID-19 and HIV.
For starters, the body creates a natural immunological response to SARS-CoV-2, but that’s not the case with HIV.
As he told the American Journal of Managed Care, “It is very difficult to get a vaccine [for HIV], because it’s very difficult to induce the body to do something that even natural infection doesn’t successfully allow it to do, [which] is to develop an adequate immune response to clear the virus,” he said. “The challenges are very, very different.”
One of the main problems in targeting HIV is its ability to vary. Studies show the amino acid sequences of the HIV protein can differ up to 20% between viruses within a particular clade and as much as 35% in virus samples from different clades.
Another problem is that HIV establishes latent viral reservoirs early on during infection, limiting the body’s immune system. It’s also not clear what immunization from HIV looks like. The body can’t get rid of the virus completely, and doctors aren’t sure what constitutes an effective immune response.
Charting a Course
Despite these challenges, Moderna is working full force towards an effective HIV vaccine. Researchers have already discovered that mRNA can yield high levels of protective antibodies in mice, which could confer protection against the virus, but they still have a long way to go.
The drug has yet to undergo human trials, but it’s expected to enter into Phase 1 trials this year. The vaccine candidate was developed in collaboration with the AIDS Vaccine Initiative and the Bill and Melinda Gates Foundation.
Messenger mRNA vaccines may be the future of medicine, helping us get rid of diseases that were once thought incurable.
