Evaluation of measles immunity in the central black sea region of Türkiye.

BACKGROUND: Eradication of the measles virus is a major requirement to promote global health. Great progress has been made in reducing the incidence of measles through vaccination efforts. In our study, we aimed to determine the levels of immunity against measles in our region and to examine the relationship between age groups and gender. METHODS: The results of patients admitted to our hospital, a tertiary care hospital located in the Central Black Sea Region in the north of Türkiye, between May 2021 and December 2024 were retrospectively analyzed. Serum samples were tested for measles-specific IgG and IgM antibodies using the LIAISON® Measles IgG and IgM (DiaSorin, Italy) chemiluminescence immunoassay (CLIA). RESULTS: A total of 5252 individuals aged ≥ 4 years were included in the study, of whom 3423 (65.2%) were female and 1829 (34.8%) were male. Overall, 70.7% of participants were seropositive for measles IgG antibodies. Measles IgG seropositivity was found in 69.5% of women and 73.0% of men; the difference between genders was statistically significant (p = 0.007). Seropositivity rates increased significantly with advancing age, ranging from 60.8% in individuals aged 4–30 years to 97.5% in those aged ≥ 41 years (p < 0.05). CONCLUSION: Identifying non-immune individuals remains an important component of measles elimination strategies. In this study, individuals aged 4–30 years exhibited lower measles IgG seropositivity compared with older age groups, suggesting a potential immunity gap in this population. Higher immunity levels observed in older age groups were consistent with differences in birth cohorts and historical measles vaccination policies. Future research evaluating the durability of vaccine-induced immunity and the potential role of additional immunization strategies may help inform evidence-based vaccination policies.