Epidemiology of Measles in the Northern Region from 2019 to 2023 and Risk Assessment for 2024

A study describing a series of cases was conducted in 28 provinces to characterise the epidemiological profile of measles during 2019–2023 and assess the potential risk of a measles outbreak in 2024. The study identified a significant outbreak in 2019, accounting for 949 out of 1,157 reported cases. Children under five years constituted 61.3% of all cases, with 79.7% having unknown or unvaccinated status. Measles-containing vaccine first dose (MCV1) coverage declined from 96.7% in 2021 to 88.5% in 2023, notably lower in mountainous provinces. Dropout rates between DPT1 and MCV1 exceeded 10% in several delta provinces. Hanoi and Nghe An had moderate risk, and Ha Tinh province was identified as a high-risk area due to low vaccination rates, population mobility, and proximity to outbreak regions. To effectively control measles and progress towards elimination goals, efforts should prioritize achieving high two-dose measles vaccine coverage while simultaneously minimizing missed vaccination opportunities and reducing dropout rates. Furthermore, strengthening the robustness and responsiveness of the measles surveillance system is a critical imperative.