Commentary on Immune Checkpoint Inhibitors and mRNA Vaccines

SARS-CoV-2 mRNA vaccination has been reported to enhance the effectiveness of immune checkpoint inhibitors (ICIs). However, the apparent doubling of survival reported in “SARS-CoV-2 mRNA vaccines sensitize tumours to immune checkpoint blockade” is inconsistent with contemporary clinical evidence. This commentary reviews confounding factors across the 2019 to 2023 pandemic period, including COVID-related mortality bias and compromised preclinical models. Post-2020 real-world survival curves for NSCLC and melanoma remain identical to pre-pandemic benchmarks, and no change has been adopted by NCCN, ASCO, or ESMO guidelines. The most reasonable explanation for the observed survival difference is protection from COVID infection rather than vaccine-induced tumour sensitization.