 The OKAPI online monitoring system was established in Germany to estimate influenza vaccine uptake among hospital staff, with questions on measles and hepatitis B added in subsequent years. Influenza vaccination coverage increased from 39.5% in 2016-17 to 52.3% in 2018-19, with physicians being more likely to be vaccinated for self-protection while nurses cited a lack of vaccine confidence, as their reason for not being vaccinated. The OKAPI platform serves as a tool to monitor and understand vaccination behavior among hospital staff, which can inform targeted interventions to increase vaccination rates. This article was authored by Julia Newfound, Ronja Wenzhel, Bert Bedecker, and others.