“…The study intervention was the learning collaborative approach taken to improve adult vaccination rates over 3 one-year collaborative periods and is reported in detail elsewhere. 11 Briefly, the learning collaboratives were led by an expert advisory committee and included in-person meetings, webinars, sharing of best practices, education, site visits, goal setting, outreach and coaching, peer-to-peer learning, case studies, and clinical outcome measurement. Participating organizations were encouraged to choose from a selection of strategies to improve their vaccination rates including, but not limited to, nurse standing orders, use of a 1-way or 2-way state vaccination information system registry, patient and provider education, patient outreach, EHR registries, health maintenance and best practice alerts, working with specialists, working with pharmacies, designating provider champions, and identifying and learning from high performers.…”