COVID-19 proved that mRNA vaccines can work. Now, researchers are applying the technology to other diseases.

More than half of Americans are fully vaccinated against COVID-19. Many of them received an mRNA vaccine that was developed by Pfizer or Moderna.

“mRNA is a blueprint to tell your cells what protein to make,” Dr. Scott Joy, an internal medicine specialist and Chief Medical Officer for HCA Healthcare Physician Services group, said.

“It’s either a protein that builds the cells, it’s a protein that fights an infection, or it’s a protein that has some other role in your body,” he added.

Though the COVID vaccines are new, research on mRNA and mRNA-based vaccines has been happening for decades.

“It’s interesting to look at the data from the late 90s from when the mRNA vaccines were being studied. The issue was not behind the basic science of why an mRNA vaccine would be effective, it was really how do you create a vehicle to get it into the cell to allow it to do what it needs to do. And that's what the last 20 years have really been about,” Dr. Joy said.

He said this technology can be applied to more than just COVID.

“We’re dedicating hundreds of employees, both in the U.S. and in Europe, to working on mRNA as one of the foundations for new vaccines,” Dr. Michael Greenberg, the vice president and medical head of Sanofi Pasteur North America, said. The company has been developing vaccines for decades.

“mRNA vaccines have been some of the ones that have gotten a lot of attention the past couple years because of their success that have been really shown during the COVID-19 pandemic,” Dr. Greenberg said.

Their efforts with mRNA started before the pandemic.

“We are the first ever to create, to start a clinical trial for seasonal flu vaccine using mRNA and so far the results are very promising,” he said.

The mRNA vaccines can be used to prevent illness in multiple ways.

“The idea was, can we develop a vaccine which is...not just focusing on one pathogen,” Dr. Gunjan Arora, a research scientist at the Yale School of Medicine, said.

Arora is part of a team working on an mRNA vaccine for Lyme disease – a tick-borne illness caused by a specific bacteria.

“The idea is if he can develop a technology where we can deliver multiple candidate antigens, can we stop ticks from feeding and eventually that would block the Lyme disease in humans,” he said.

Essentially, the vaccine would target antigens found in tick saliva, preventing it from feeding on people and reducing transmission.

Researchers say the advancement of mRNA COVID vaccines shows a lot of potential for mRNA use.

“Acceptability of any new technology requires a breakthrough, a validation process. Which I think COVID-19 has done in this case,” Arora said.

“With the success of these out of the gate, we're pretty excited about future opportunities as well,” Joy said.

mRNA has been a game-changer for the development of a COVID-19 vaccine. It has allowed researchers to more efficiently engineer a less intrusive vaccine as it instructs your body to produce certain proteins rather than have your immune adjust to small bits of the virus it is trying to combat.

The mRNA technology has been used, in theory, since the 1990s, but the Pfizer and Moderna COVID-19 vaccines are the first time the technology has been put into practice for human use.

“It’s really fun to be part of this development,” said Sven Even Borgos, a researcher with SINTEF, one of Northern Europe’s largest research institutes. “The basic principle of mRNA is that when you deliver this code, you actually instruct the body to make its own medicine and that’s partly why it’s so fascinating.”

With the COVID-19 vaccines, the mRNA that is injected into the body instructs it to produce small bits spike protein, the main way through which the coronavirus injects itself into our cells. This way, the body recognizes the spike protein and attacks any cells that have it, such as COVID-19.

Researchers say that same mRNA technology has been a game-changer for a slew of other viruses and disorder such as cancer, sports recovery, and preexisting conditions.

“There are certain things that we could never do before without being able to use DNA, or mRNA, to put new proteins into cells,” said Bruce Zetter, the head researcher at Boston Children’s Hospital and a professor of cancer biology at Harvard Medical School.

He says mRNA is not a silver bullet, but it is a monumental step in accelerating cancer research.

“Let’s say we had a cancer cell in someone’s body and we knew it made a particular protein that normal cells don’t make,” he said. “I’ll call [that particular protein] ‘Cancer Protein 1.’ So we have CP-1, and now, what I would do is I would get mRNA to specify CP1. I’d inject it into the muscle in the arm and those cells in the muscle would make CP1 and they’d stimulate my immune system to fight any cell that had that protein.”

Currently, many cancer treatments rely on radiation to kill cancer cells. Through mRNA, however, Zetter says we are training our immune systems to act as the primary fighter.

“It’s almost like you could treat virtually any disease with it because almost all diseases in your body have a connection to a protein of some kind,” said Borgos.

Researchers say mRNA could tell the body to produce proteins to make ligaments, helping patients recovering from a torn ACL.

It could also help autoimmune disorders like hemophilia, which can causes excessive bleeding, as it instructs the body to produce a protein that allows blood to clot properly.

Just a few weeks ago, researchers in Germany injected mice with mRNA, which reduced the activity of multiple sclerosis in those mice. Currently, there is no cure for the disease.

Researchers say we are still years from any type of vaccines for these diseases but say mRNA has sped up their development considerably.

“It’s really a revolution in vaccine technology,” said Borgos.