BackgroundIn response to the severe hepatitis A outbreak that occurred in Michigan between August 2016 and September 2019, our multihospital health system implemented an electronic medical record (EMR)-based vaccination intervention across its nine emergency departments (EDs). The objectives were to explore the impact of this intervention on increasing vaccination rates among high-risk individuals and to assess the barriers to use of a computerised vaccine reminder system.MethodsAll patients who were 18 years or older were screened using an electronic nursing questionnaire. If a patient was at high risk based on the questionnaire, an electronic best practice advisory (BPA) would trigger and give the physician or advanced practice provider the option to order the hepatitis A vaccine. We explored the vaccination rates in the 24-month preintervention and the 18-month intervention periods. We then administered a survey to physicians, advanced practice providers and nurses evaluating their perceptions and barriers to use of the EMR intervention.ResultsDuring the preintervention period, 49 vaccines were ordered (5.5 per 100 000 patient visits) and 32 were administered (3.6 per 100 000 patient visits). During the intervention period, 574 865 patient visits (74.3%) were screened. 2494 vaccines (322 per 100 000 patient visits) were ordered, and 1205 vaccines (155 per 100 000 patients visits) were administered. Physicians and advanced practice providers were initially compliant with the BPA’s use, but compliance declined over time. Surveys revealed that the major barrier to use was lack of time.ConclusionsEMR screening tools and BPAs can be used in the ED as an effective strategy to vaccinate high-risk individuals. This may be translatable to outbreaks of other vaccine-preventable illnesses like influenza, measles or SARS-CoV-2. Providing ongoing education about the public health initiative and giving feedback to physicians, advanced practice providers and nurses about tool compliance are needed to sustain the improvement over time.