mRNA Covid Vaccines May Supercharge Cancer Treatments, Doubling Survival Rates in New Study

The mRNA Covid-19 vaccines might have an unexpected life-extending benefit for people undergoing cancer treatment, according to new research. Scientists say the vaccines appear to enhance the effects of immunotherapy drugs, potentially helping cancer patients live nearly twice as long.

An analysis of nearly 1,000 patients with advanced lung and skin cancers found that those who received an mRNA Covid-19 vaccine within 100 days of starting immune checkpoint inhibitors survived significantly longer than those who did not. Researchers now plan to test these findings in a clinical trial expected to begin later this year.

“The results are just remarkable,” said Dr. Elias Sayour of the University of Florida, who led the research. “Could we one day create an mRNA vaccine that activates the immune system in every cancer patient? The potential is enormous.”

However, Sayour cautioned that it’s too soon to change medical practice. “I wouldn’t recommend vaccination solely for this purpose until it’s proven in clinical trials,” he said. “When you’re using the immune system to fight cancer, there are always risks involved.”

The body’s immune system routinely destroys abnormal cells before they turn into cancer. But some tumors find ways to escape detection by shutting down this defense mechanism. They do this by exploiting “off switches” on immune cells known as T-cells — the body’s primary cancer fighters.

One such switch is a protein called PD-1. When PD-1 binds to another protein, PD-L1, on the surface of healthy cells, it sends a signal telling T-cells not to attack. Many cancers produce large amounts of PD-L1 to hide from the immune system.

Checkpoint inhibitors — drugs that block these off switches — have revolutionized cancer treatment and earned their inventors the 2018 Nobel Prize in Medicine. By preventing PD-1 and PD-L1 from interacting, these drugs allow T-cells to recognize and destroy cancer cells.

However, checkpoint inhibitors don’t work for everyone. Their success depends on whether the immune system has already recognized the tumor. If not, the drugs can do little to help.

Scientists have long explored the idea of combining vaccines with checkpoint inhibitors to strengthen the immune response. Cancer vaccines are usually customized to target unique mutations in a patient’s tumor, but they are expensive and complex to produce.

During vaccine trials, Sayour’s team made a surprising discovery: even non-specific mRNA vaccines — those not designed to target cancer — seemed to boost anti-tumor activity. “That was an absolute surprise,” said Sayour.

In animal studies published earlier this year, the researchers found that mRNA vaccines trigger a powerful immune “alarm,” alerting T-cells and causing them to move from tumors to lymph nodes. There, they activate other immune cells that mount a stronger, more coordinated attack against cancer.

Realizing this might apply to Covid-19 mRNA vaccines, the team examined real-world data from cancer patients.

Researchers analyzed patient records from the University of Texas MD Anderson Cancer Center. Of 884 patients with advanced lung cancer treated with checkpoint inhibitors, 180 had received an mRNA Covid-19 vaccine within 100 days of starting treatment. Those patients lived a median of 37 months, compared with 20 months for those who were not vaccinated within that window.

A similar pattern emerged among melanoma patients. Of 210 people with advanced disease, 43 received an mRNA vaccine within 100 days of beginning immunotherapy. Their survival ranged from 30 to 40 months, compared to 27 months for those unvaccinated in that timeframe. Because many vaccinated patients were still alive when the study ended, researchers believe their survival advantage could be even greater.

The findings were presented at the European Society for Medical Oncology Congress in Berlin, Germany.

There have also been individual reports of tumors shrinking after mRNA Covid-19 vaccination, even in patients not receiving checkpoint inhibitors. “It’s possible the vaccine itself can stimulate an anti-tumor response,” Sayour said. “But we need more research to confirm that.”

Despite these promising results, the U.S. government recently announced funding cuts for mRNA vaccine development. Many scientists worry that reducing support now could slow progress on what may become a powerful new weapon against cancer.

“mRNA technology changed the course of the pandemic,” Sayour said. “If this link holds true, it could also change how we treat cancer — not by replacing immunotherapy, but by making it work better for more people.”