An analysis of nearly 1,000 cancer patients shows that mRNA covid-19 vaccines, given soon after starting immune checkpoint inhibitors, nearly doubled survival times for advanced lung and skin cancers. The findings, presented at a medical congress in Berlin, suggest an unexpected immune boost from the vaccines. A clinical trial to confirm these results is set to begin before year's end.
Researchers have uncovered a potential side benefit of mRNA covid-19 vaccines: enhancing the effectiveness of immunotherapy for certain cancers. In an analysis of patient records from the University of Texas MD Anderson Cancer Center, those who received an mRNA covid-19 vaccine within 100 days of beginning immune checkpoint inhibitors showed significantly longer survival compared to unvaccinated patients.
For advanced lung cancer, among 884 patients treated with checkpoint inhibitors, 180 who were vaccinated within the 100-day window had a median survival of around 37 months, versus 20 months for the others. In metastatic melanoma, out of 210 patients, 43 vaccinated early achieved survival times of 30 to 40 months, compared to 27 months for those not vaccinated within that period; some vaccinated patients remain alive, potentially extending this figure further.
The results were presented today at the European Society for Medical Oncology Congress in Berlin, Germany. "The results are just remarkable," said Elias Sayour at the University of Florida, who envisions mRNA vaccines as a "master key" to awaken broad immune responses against cancer.
Checkpoint inhibitors, which earned a Nobel Prize in 2018, block proteins like PD-1 and PD-L1 that tumors use to evade T-cells. However, their success depends on an active immune response. Sayour's team previously found in mouse studies that mRNA vaccines, even non-specific ones like those for covid-19, trigger an innate immune "siren" that mobilizes T-cells toward tumors.
While promising, Sayour cautions against unproven recommendations: "I don’t like making clinical recommendations unless things are proven." Patients should follow standard vaccine guidelines. Case reports have noted tumor shrinkage post-vaccination without immunotherapy, but more research is needed.