Vaccine safety for individuals receiving immune checkpoint inhibitor therapy: A narrative review of current literature and recommendations for future research

Some individuals with cancer may receive immunomodulatory treatment such as immune checkpoint inhibitors (ICIs). ICIs are now part of standard of care for many cancers and have improved survival for cancer patients. However, they are also associated with immune-related adverse events (irAEs), which can affect any organ or system, and can range from mild to severe. It has been hypothesized that vaccination of these individuals could increase the risk of irAEs or other vaccine-associated adverse events. This narrative review of 28 primary research articles presents findings from existing literature on vaccine safety for individuals receiving ICIs, and makes recommendations for future research on this topic. The existing evidence suggests that influenza and COVID-19 vaccines are safe for individuals receiving ICIs and do not pose additional risks of irAEs beyond baseline risks associated with ICI therapy.