Could mRNA vaccines usher in a new era of cancer treatment?

The millions of doses of mRNA vaccines administered worldwide may significantly enhance the effectiveness of immunotherapies against cancer, according to US researchers presenting at a major oncology conference in Germany. Could this mark the beginning of a new era in oncology?

Doctors from the M.D. Anderson Cancer Centre at the University of Texas told the European Society for Medical Oncology (ESMO) conference in Berlin that cancer patients who happened to receive an mRNA COVID-19 vaccine within the first 100 days of starting immunotherapy lived longer than those who did not, as reported by German media outlets.

One example is a 72-year-old woman from Greece who suffered from skin cancer. After receiving two doses of BioNTech’s mRNA COVID-19 vaccine during the pandemic, the cancerous lesions on her skin shrank to about half their size. Following a third shot, they became even smaller. Apparently, the vaccine stimulated her immune system to attack the cancer itself — at least, that’s what her doctors believe. They reported her case in the scientific journal Vaccines in 2022. Several similar individual cases have since reinforced this hypothesis.

Intrigued by reports like that of the Greek patient, the Texas researchers analysed the medical records of more than 1,000 people with advanced skin or lung cancer treated at the M.D. Anderson Cancer Centre between 2019 and 2023.

Among 884 patients with advanced lung cancer, those who received an mRNA COVID-19 vaccine alongside their immunotherapy survived an average of 37 months. In contrast, those who were not vaccinated survived only 20 months on average. The 210 patients with malignant melanoma who were vaccinated also lived significantly longer. Other, non-mRNA vaccines did not have the same effect.

“It looks as though the mRNA vaccine can wake up the immune system and position it to fight the cancer,” said Steven Lin the M.D. Anderson Cancer Centre, the study’s lead author. Could the connection simply be a coincidence — perhaps because only healthier patients were vaccinated, or because protection from COVID-19 extended their lives? Lin argues otherwise, citing meticulous data analysis and additional experiments on mice and humans. According to their findings, mRNA vaccination not only triggers a specific immune response against the coronavirus but also activates a broader, fundamental immune response involving the release of large amounts of immune messengers — chiefly interferons. These, in turn, activate T cells that combat both viruses and cancer.

“The data are very convincing,” said immunology professor Christine Falk of Hannover Medical School. “The immune system basically has the ability to destroy cancer cells; it does so constantly,” she explained. “If cancer develops nonetheless, it’s because the immune system becomes powerless against these malignant cells — for example, because they camouflage themselves particularly well or actively suppress the immune response.” In other words, cancer cells “press an off-switch” on the immune cells trying to attack them.

Steven Lin and his team hope that a universal mRNA vaccine can eventually be developed for use in all cancer patients to boost their immune response. Even greater results, however, may come from personalised mRNA vaccines tailored to an individual’s specific tumor cells. Work on such therapies is underway globally — including at BioNTech in Mainz, the company that created the first mRNA COVID-19 vaccine.

By Nazrin Sadigova