Staff Contact: Mat Reidhead or Jackie Gatz
Understanding the drivers of the likelihood of individuals failing to receive the required second booster dose of Pfizer and Moderna COVID-19 vaccines will be critical in optimizing allocations of the newly approved single-dose Johnson & Johnson vaccine. Through March 1, 56,720 individual Missourians have not received booster doses within the manufacturer-prescribed window of 21 days for Pfizer and 28 days for Moderna. This accounts for roughly 6.5% of all individuals who have received any dose in Missouri, and among those, only 1,817 are beyond the latest guidance from the Centers for Disease Control and Prevention that recommends booster doses be administered within 42 days of the first dose. Nationally, the rate of series incompletion is 12%. One of the factors contributing to the high second dose completion rate in Missouri is the COVID-19 Vaccine Navigator program — a one-stop shop for vaccine registration, event location and second dose reminders.
Due to high frequencies of ShowMeVax records missing race, it is difficult to evaluate completed booster rates along demographic lines. However, a near-monotonic relationship exists between poverty of the recipient’s ZIP code and the percent of total vaccine recipients that are overdue for the booster dose. This signals the potential for the single-dose J&J vaccine to be an effective strategy in fully protecting socially vulnerable populations. Additionally, while the distribution of vaccines to date has been driven by phase-eligible individuals and not the total population, a pattern is emerging that suggests an inverse relationship between poverty and the percent of total doses received to date across Missouri’s communities. The continued monitoring of this disparity will be critical as the state aims to increase vaccine acceptance in underserved communities.