Abstract
<jats:p>Introduction: Co-administration is a safe and effective vaccination practice and is considered an important strategy for increasing vaccination coverage across populations. However, the real world uptake for respiratory co-administration is not well quantified. Objective: To better characterize rates of co-administration and potential missed opportunities. Methods: This retrospective study leveraged data from a large vaccine ecosystem that provides end-to-end vaccine management for more than 5,000 clinics located in 43 US states. Data were gathered from the vaccine ecosystem database for active patients, defined as those who were eligible for vaccination with at least one of three respiratory vaccines (COVID-19, influenza, and Respiratory syncytial virus [RSV]), had a clinic visit between July 1, 2022 and June 1, 2023, and received one or more of those vaccine(s) during the study period. Active patients were categorized according to the number and types of those vaccines received. Those receiving co-administration of vaccines were compared to those who did not receive co-administration. Results: Of the 1,233,349 patients who received at least one respiratory vaccine during the study period, 50,582 active patients (4.1%) received 2 or more co-administered vaccines. Middle-aged adults (51-64 years), women, commercially insured patients, and those vaccinated in primary care clinics and health departments were more likely to receive co-administered vaccines. The most commonly co-administered respiratory vaccines were influenza and COVID-19 (91.3%), followed by influenza and RSV (5.4%) and RSV and COVID-19 (2.5%). Only 0.7% of patients in the co-administration cohort received all 3 respiratory vaccines simultaneously. Conclusions: This study highlights substantial missed opportunities for co-administration of respiratory vaccines and identifies population- and clinic-level factors associated with higher uptake.</jats:p>