Measles Vaccine Coverage Stagnates in Central Ohio Following 2022 Outbreak
A recent study published in JAMA Network Open reveals that measles, mumps, and rubella (MMR) vaccination rates in central Ohio remain significantly below the level needed for herd immunity, even after a considerable outbreak in late 2022. The outbreak, centered near Columbus, affected 90 children under the age of 15, with the Somali community disproportionately impacted in its early stages.
Researchers analyzed electronic medical records from a large primary care network serving the region, tracking MMR vaccination coverage among nearly 150,000 children aged 15 and under who had recent well-child visits. Data was collected at the outbreak’s onset (October 2022), 12 months later (October 2023), and 20 months later (June 2024).
The study found little change in timely first-dose (MMR1) vaccination rates,remaining consistently around 53.6% throughout the 20-month period. While timely second-dose (MMR2) vaccination saw a slight increase – from 57.9% to 60.2% – overall coverage remained well below the 93% threshold required to prevent widespread transmission.
Significant disparities in vaccination rates persisted between children of Somali descent and those of non-Somali descent. At the start of the study, only 35.7% of Somali children had received their first MMR dose on time, compared to 55.4% of non-Somali children - a gap of nearly 20 percentage points. This gap widened over time, reaching 22.1 percentage points at 20 months. Though, by 20 months, approximately 78% of both Somali and non-Somali children had received at least one MMR dose, regardless of timing. Coverage rates for the second dose were statistically similar between the two groups at 20 months (around 60%).
The authors suggest these disparities may be linked to structural, cultural, or informational barriers to vaccination. They noted that the gap narrowed as children aged and became eligible for catch-up vaccinations through pre-kindergarten visits or school entry requirements.
The study’s findings highlight the ongoing vulnerability of the central Ohio pediatric population to future measles outbreaks and emphasize the critical need for increased investment in proactive surveillance and targeted vaccination outreach efforts.
