Measles Outbreaks and Implications for Patients Receiving Stem Cell or Cellular Therapies in Canada: Cell Therapy Transplant Canada (CTTC) Infectious Diseases Working Committee.

Measles exposures have historically been rare since the introduction of routine vaccination programs, resulting in a lack of attention from cancer patients, hematopoietic stem cell transplant (HCT) recipients, patients receiving cellular therapy (CT) and their healthcare providers. It is essential to acknowledge the importance of vigilance in these situations. Measles herd immunity has declined significantly in North America due to rising vaccine hesitancy, resulting in outbreaks. Measles can result in severe outcomes, and its reemergence has raised alarm among patients and healthcare professionals caring for HCT/CT recipients. Patients with severe immunocompromising conditions cannot receive live-attenuated vaccines, such as the measles vaccine. The lack of data on measles prevention in this vulnerable group presents significant clinical challenges. In response, Cell Therapy Transplant Canada (CTTC) Infectious Diseases Working Committee has developed a set of frequently asked questions to provide expert guidance to HCT and CT recipients, acknowledging the limited evidence base.