What story do antibodies tell: Population immunity of Belgrade residents as a guide for future steps

Abstract

U okviru projekta „Procena imuniteta stanovnistva na vakcinama preventabilne i druge infekcije u populaciji stanovnika grada Beograda”, sprovedena je seroepidemiološka studija preseka s ciljem procene seroprevalence IgG antitela na morbili virus, mumps virus i rubela virus. Analizirani su uzorci seruma 2533 dobrovoljaca, raspoređenih u devet starosnih kategorija (1–70+ godina), primenom standardizovanih ELISA metoda. Rezultati su pokazali varijabilne nivoe seropozitivnosti u zavisnosti od vakcinalnog statusa i starosne kohorte. Ukupna seroprevalenca morbila iznosila je 74,7%, s visokim nivoima u dece (90,7%) i starijih osoba (98,4%), dok je najniža detektovana bila u grupi od 30–49 godina. Procenat seropozitivnosti na rubelu bio je 94,8%, sa ujednačenom raspodelom među svim starosnim grupama. Seroprevalenca mumpsa iznosila je 85,1%, s najnižim vrednostima kod dece uzrasta 1–5 godina (76,1%) i najvišim kod starijih ispitanika (92,6%). Rezultati ukazuju na solidan kolektivni imunitet populacije Beograda, ali i na potrebu za revakcinacijom ili dodatnim epidemiološkim merama medju pojedinim grupama, posebno u kontekstu malih boginja kod odraslih srednje dobi i zaušaka kod dece. Neophodna je kontinuirana procena efikasnosti vakcinacije i sprovođenje ciljanih imunizacionih strategija kako bi se očuvao kolektivni imunitet i smanjio rizik od izbijanja epidemija. Zaključci ove studije mogu doprineti optimizaciji nacionalnih programa imunizacije i definisanju adekvatnih javnozdravstvenih preporuka.As part of the project “Assessment of Population Immunity to Vaccine-Preventable and Other Infections in the Population of Belgrade”, a cross-sectional seroepidemiological study was conducted to evaluate the seroprevalence of IgG antibodies against measles virus, mumps virus, and rubella virus (MMR). Serum samples from 2533 voluntary participants, distributed across nine age categories (1– 70+ years), were analyzed using standardized ELISA methods. The results revealed variable levels of seropositivity depending on vaccination status and age cohort. The overall seroprevalence of measles was 74.7%, with high levels detected in children (90.7%) and older adults (98.4%), while the lowest seropositivity was observed in the 30–49 age group. The seropositivity rate for rubella was 94.8%, with a uniform distribution across all age groups. The seroprevalence of mumps was 85.1%, with the lowest values recorded in children aged 1–5 years (76.1%) and the highest in older adults (92.6%). The results indicate a solid level of herd immunity in the population of Belgrade but highlight the need for revaccination or additional epidemiological measures among certain groups, particularly regarding measles immunity in middle-aged adults and mumps immunity in children. Continuous assessment of vaccination efficacy and the implementation of targeted immunization strategies are necessary to maintain herd immunity and reduce the risk of epidemic outbreaks. The conclusions of this study may contribute to the optimization of national immunization programs and the development of appropriate public health recommendations