MD Anderson

ESMO 2025: COVID vaccines linked to longer survival in patients with lung cancer, melanoma

October 24, 2025

Patients with cancer who received an mRNA-based COVID vaccine within 100 days of starting immune checkpoint therapy were twice as likely to be alive three years after treatment compared with those who never received a vaccine, according to results presented at the European Society for Medical Oncology (ESMO) congress.

The retrospective study analyzed >1,000 patients treated between August 2019 and August 2023. Among 180 patients with advanced non-small cell lung cancer, median survival was 37.3 months for vaccinated individuals vs. 20.6 months for 704 unvaccinated patients. In metastatic melanoma, median survival hadn't yet been reached in 43 vaccinated patients, compared with 26.7 months in 167 unvaccinated patients. Notably, patients with immunologically “cold” tumors—typically resistant to immunotherapy—experienced nearly a five-fold improvement in three-year overall survival after vaccination.

Mechanistic studies suggest mRNA vaccines prime the immune system, increasing PD-L1 expression on tumors and creating an optimal environment for checkpoint inhibitors. These findings have prompted a randomized phase 3 trial to determine whether mRNA COVID vaccines should become part of standard care for patients receiving immunotherapy.

Source:

(2025, October 19). MD Anderson Cancer Center. ESMO 2025: mRNA-based COVID vaccines generate improved responses to immunotherapy [News release]. https://www.mdanderson.org/newsroom/research-newsroom/-esmo-2025--mrna-based-covid-vaccines-generate-improved-response.h00-159780390.html