MRNA COVID Vaccines Boost Immunotherapy Survival in Lung Cancer, Melanoma

A retrospective analysis of more than 1,000 patients at MD Anderson, presented at the 2025 ESMO Congress and reported in Nature, found that cancer patients who received an mRNA COVID-19 vaccine within 100 days of starting immune checkpoint inhibitors were about twice as likely to be alive three years after beginning treatment compared with those who were not vaccinated. Researchers propose that mRNA vaccines nonspecifically “train” or mobilize the immune system—potentially acting as a medium-strength stimulus that boosts antitumor responses—and say the result points toward the possibility of an off‑the‑shelf, universal cancer vaccine. Experts not involved in the work call the data promising but urge caution, noting the biological plausibility (a “Goldilocks” immune boost) and the remaining uncertainties. The authors and other groups are planning randomized Phase 3 trials to validate the retrospective findings before changing practice. In the meantime, clinicians and patients are advised to follow existing vaccination guidelines because the results, while encouraging, are preliminary and the approach carries potential risks that must be evaluated in controlled trials.