Do mRNA vaccines hold the key to stopping cancer in its tracks? Northeastern University vaccine experts talk recent developments.
There’s a budding scientific literature supporting the idea that so-called messenger RNA vaccines, in prompting a robust immune response inside the body, can help cancer patients.
The COVID-19 vaccines could be doing a lot more than just warding off viral infection: they may be teaching our immune systems how to fight cancer more effectively.
There’s a growing body of scientific literature supporting the idea that so-called messenger RNA (mRNA) vaccines, by prompting a robust immune response within the body, can help cancer patients. And Northeastern University vaccine experts say the pandemic-era tech holds real promise as a tool to combat one of the world’s deadliest diseases.
“There is ample evidence showing how mRNA technology can transform how we prevent and treat diseases, including these cross benefits that we’re starting to see in cancer patients,” says Mansoor Amiji, university distinguished professor of pharmaceutical sciences and chemical engineering.
Amiji and his colleagues have been working on novel mRNA delivery systems. As part of that work, he’s been focused not only on how to make vaccines safer and more effective, but also easier to store without deep freezing them.
Unlike traditional vaccines that use weakened or inactivated viruses, mRNA vaccines work by giving the body genetic instructions to make a small component of a specific protein, then training the immune system to recognize and attack the real pathogen — or, in the case of cancer vaccines, diseased cells — when they show up.
The American Cancer Society states that mRNA vaccines “might prove to be useful” in treating cancers by teaching the immune system to recognize cancer-cell proteins.
Some cancer-related vaccines have already proven effective, such as preventive vaccines against Human Papillomavirus (HPV) and hepatitis B. There are also therapeutic vaccines that aim to treat existing cancers by training the immune system to recognize and attack tumor-specific proteins.
Preventive vaccines are already in widespread use, but most therapeutic cancer vaccines — including mRNA-based ones — are still in clinical trials.
But one retrospective study published last week in Nature proves just how versatile mRNA vaccines can be, finding that cancer patients who received a COVID-19 mRNA vaccine lived noticeably longer than their unvaccinated counterparts while undergoing immunotherapy.
Researchers analyzed data from more than 1,000 patients with advanced non-small cell lung cancer and melanoma. Researchers divided them into two groups: those who received an mRNA COVID-19 vaccine and those who did not. What they found was that patients who received the shot within 100 days of starting immunotherapy had a median survival of 37.3 months, nearly double the 20.6 months seen in patients who were not vaccinated.
The researchers also concluded in a separate analysis that the mRNA vaccination administered in tandem with immunotherapy slowed tumor growth in mice.
“This is specific to the mRNA vaccines, so either the Moderna or Pfizer mRNA vaccines are the ones creating this cross-benefit in cancer patients,” Amiji says.
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Brandon Dionne, associate clinical professor of pharmacy and health systems sciences, says the results “aren’t entirely surprising,” based on other in-vitro data and animal studies suggesting that the mRNA vaccines “prime the immune system” and generate a “non-specific response” that may help the body combat other diseases.
The COVID shots work with respect to these cancers because they work in concert with immune checkpoint inhibitors, which are drugs that prevent tumors from turning on checkpoints that dampen immune response to the cancer cells.
“The combination is simultaneously preventing the cells from blocking an immune response, and then also prompting a stronger immune response that then starts to attack the cancer cells,” Dionne says
Dionne notes that the first clinical trial involving an mRNA vaccine was to treat prostate cancer.
The experts note that the field of medicine is filled with examples of therapies with cross-benefits, with one of the most prominent examples being GLP-1 medications, such as Ozempic and Wegovy. Originally designed to regulate blood sugar in diabetes patients, they’re now widely used as weight loss drugs.
Similarly, drugs now used to treat erectile dysfunction began as medications to treat pulmonary hypertension, Dionne says. Other drugs, such as antibiotic azithromycin, have demonstrated non-specific therapeutic effects beyond their original uses.
“In order to properly sensitize your immune system to attack tumors, you need to prime it,” Amiji says. “And right now, with certain cancers — especially lung cancer and melanoma — these tumors are what we call ‘cold’ tumors, meaning they don’t allow our immune cells to infiltrate and do their job.”
Researchers are finding that mRNA vaccines can help convert these cold tumors into “hot” ones, prompting the immune system to respond more effectively. The effect appears strongest in patients who are pre-vaccinated, or who receive an mRNA shot around the time they begin treatment, Amiji says.
So-called “hot” tumors are packed with immune cells actively fighting cancer, making them more responsive to treatments like immunotherapy. “Cold” tumors, on the other hand, have very few immune cells inside or around them, meaning the body’s defenses have a hard time recognizing the cancerous tissue. Because the immune system isn’t activated in these areas, the tumors are harder to target with treatments like immunotherapy.
Researchers are now exploring whether vaccines might help “wake up” cold tumors and improve immune responses, a question that Amiji says warrants further study.
“Imagine if we analyze the data retrospectively to compare vaccinated and unvaccinated patients — could we determine whether the COVID vaccine was effective in preventing cancer in the first place?” Amiji says. “We’d obviously need to do that study with a larger cohort, but that would be a remarkable finding.”
