Mumps to COVID-19: Vaccinated persons remain vulnerable when community uptake is low.

Vaccines against coronavirus disease 2019 (COVID-19) first became available in the United States and Europe outside clinical trials in December 2020, when administration began in high-priority populations such as healthcare workers and long-term care residents. [1] Since that time, global rollout progresses with wide variation in vaccination rates by country. [2] Depending upon product and SARS-CoV-2 variant, vaccine efficacies against infection range from approximately 70 to well over 90%, higher against severe disease. Well-resourced settings are starting to focus on booster doses among high risk persons, and locations with higher vaccination rates appear to have less COVID-19 patient and community impact. Yet, in every setting, primary vaccination to as many persons as possible remains incredibly important to effective pandemic risk management. Why this is the case, why even in settings with comparatively high vaccination rates and boosting we still should make the case that more primary vaccination matters can be answered by remembering mumps, and applying those lessons to promoting vaccine access.