A new study from The University of Texas MD Anderson Cancer Center suggests that patients who received an mRNA COVID vaccine shortly before or after starting immunotherapy lived significantly longer than those who were not vaccinated.
Researchers found that people who received an mRNA vaccine within 100 days of beginning immune checkpoint therapy were twice as likely to be alive three years later compared with unvaccinated patients. The findings were presented at the 2025 European Society for Medical Oncology (ESMO) Congress and published in Nature.
Why Would a COVID Vaccine Affect Cancer?
The research team discovered that mRNA vaccines can “wake up” the immune system, putting it on alert to detect foreign threats — including cancer cells. In response, some cancer cells begin making a protein called PD-L1 to protect themselves. Immunotherapy drugs that block PD-L1 then become more effective at helping the immune system fight the cancer.
What Did the Study Show?
- Among patients with advanced non-small cell lung cancer, those who received an mRNA vaccine had a median survival of 37 months, compared with about 21 months for those who were not vaccinated.
- In patients with metastatic melanoma, survival was also dramatically improved, especially in those with tumors that typically do not respond well to immunotherapy.
- The benefit was consistent regardless of which mRNA vaccine patients received or how many doses they got.
What Comes Next?
Based on these results, researchers are launching a randomized Phase III trial to determine whether mRNA COVID vaccines should be used routinely alongside immunotherapy.
Reference
Grippin AJ, Marconi C, Copling S, et al. SARS-CoV-2 mRNA vaccines sensitize tumours to immune checkpoint blockade. Nature. 2025 Oct 22.
