New research suggests Pfizer and Moderna�s mRNA COVID-19 vaccines could offer an unexpected boost for some cancer patients. A study has found that people with advanced lung or skin cancer lived significantly longer if they received an mRNA COVID-19 vaccine within 100 days of starting immunotherapy. Researchers say it�s not about protection from the virus � it�s about the mRNA molecule itself, which seems to �activate� the immune system and help cancer drugs work better.