SARS-CoV-2 mRNA vaccines sensitize tumours to immune checkpoint blockade

Immune checkpoint inhibitors (ICIs) extend survival in many patients with cancer but are ineffective in patients without pre-existing immunity1–9. Although personalized mRNA cancer vaccines sensitize tumours to ICIs by directing immune attacks against preselected antigens, personalized vaccines are limited by complex and time-intensive manufacturing processes10–14. Here we show that mRNA vaccines targeting SARS-CoV-2 also sensitize tumours to ICIs. In preclinical models, SARS-CoV-2 mRNA vaccines led to a substantial increase in type I interferon, enabling innate immune cells to prime CD8+ T cells that target tumour-associated antigens. Concomitant ICI treatment is required for maximal efficacy in…