INTRODUCTION: Mumps data were analysed to assess the effect of vaccination on mumps complications and hospitalisation. METHODS: The mumps cases reported to the Czech nationwide surveillance system from 2013 to 2022 were analysed using logistic regression with an odds ratio (aOR) adjusted for age, sex, year of onset and administrative region to measure the association between vaccination and complications or hospitalisation. Adjusted vaccine effectiveness (aVE) was calculated: aVE=(1-aOR)x100. RESULTS: A total of 11,913 mumps cases were reported, of which 6,885 (58%) were male. The median age of the study participants was 16 (range: 0-89 years). No complications occurred in 91% of patients. Mumps orchitis occurred in 633 (9%) male cases. A total of 946 (8%) patients required hospitalisation. The highest proportion of complications and hospitalisations was in the age group 35-44 years. Two doses of vaccine reduced statistically significantly the risk of any complications and of hospitalisation compared with unvaccinated patients: aOR 0.48 (95% CI: 0.37, 0.62), aVE of 52% (95% CI: 38, 63); and aOR 0.43 (95% CI: 0.33, 0.56), aVE of 57% (95% CI: 44, 67), respectively. Two doses showed statistically significant aVE 50% (95% CI: 32, 64) against orchitis, and 59% (95% CI: 23, 79) against meningitis. Among the two-dose recipients, the proportion of complications increased gradually with the time from the second dose. CONCLUSIONS: Our findings demonstrated a protective effect of two-dose vaccination against mumps complications and hospitalisation for mumps. We recommend continuing routine childhood mumps vaccination and maintaining high MMR coverage in Czechia.

UVOD: Analizirali smo podatke o mumpsu, da bi ocenili učinek cepljenja na zaplete in hospitalizacijo zaradi mumpsa. METODE: Primere mumpsa, ki so bili v obdobju 2013–2022 prijavljeni v državni sistem nadzora na Češkem, smo analizirali z logistično regresijo z razmerjem obetov (aOR), prilagojeno glede na starost, spol, leto začetka in upravno regijo, da bi ugotovili povezavo med cepljenjem in zapleti ali hospitalizacijo. Izračunali smo prilagojeno učinkovitost cepiva (aVE): aVE = (1 – aOR) x 100. REZULTATI: Skupaj je bilo prijavljenih 11.913 primerov mumpsa, od tega 6885 (58 %) pri moških. Povprečna starost udeležencev v študiji je bila 16 let (razpon: 0–89 let). Pri 91 % bolnikov ni prišlo do zapletov. Mumps orhitis se je pojavil pri 633 (9 %) moških. Skupaj je 946 (8 %) bolnikov potrebovalo hospitalizacijo. Največji delež zapletov in hospitalizacij je bil v starostni skupini 35–44 let. Dva odmerka cepiva sta statistično pomembno zmanjšala tveganje za nastanek morebitnih zapletov in hospitalizacijo v primerjavi z necepljenimi bolniki: aOR 0,48 (95 % IZ: 0,37, 0,62), aVE 52 % (95 % IZ: 38, 63) in aOR 0,43 (95 % IZ: 0,33, 0,56), aVE 57 % (95 % IZ: 44, 67). Dva odmerka sta pokazala statistično pomembno aVE 50 % (95 % IZ: 32, 64) v primerjavi z orhitisom in 59 % (95 % IZ: 23, 79) v primerjavi z meningitisom. Delež zapletov med prejemniki dveh odmerkov se je postopoma povečeval s časom od drugega odmerka. ZAKLJUČKI: Naše ugotovitve so pokazale zaščitni učinek cepljenja proti zapletom in hospitalizaciji zaradi mumpsa. Priporočamo nadaljevanje rutinskega cepljenja otrok proti mumpsu in ohranjanje visoke stopnje precepljenosti s cepivom OMR na Češkem.

• Keywords
• Hospitalisation, Mumps, Mumps complications, Orchitis, Vaccination, Vaccine effectiveness, cepljenje, hospitalizacija, mumps, učinkovitost cepljenja, zapleti,
• Publication type
• Journal Article MeSH

Mumps outbreaks, especially in adolescents and young adults, have been reported in the Czech Republic. The aim of the presented study was to determine the seroprevalence of specific IgG antibodies against mumps in the adult population of the Czech Republic. The study was designed as a multicenter serological survey of adults aged 18 years and over. Specific IgG antibodies against mumps were detected in blood samples using an enzyme-linked immunosorbent assay (ELISA). A total of 1,911 serum samples were examined. The overall seropositivity reached 55.3%. In individual age groups, the highest seropositivity 63% (63.5-65.2%) was recorded in adults aged 40 years and over; the lowest seropositivity was found in adults aged 18-29 years (27.4%). The difference in seropositivity rate between the 18-29 years age group and the 40 years and over age groups was statistically significant (p < 0.001). Only the 18-29 years age group included both vaccinated and unvaccinated (born in the pre-vaccine era) individuals. In vaccinated individuals, seropositivity was reported in only 19.1% of persons; in unvaccinated individuals, seropositivity reached 48.2%. Our results demonstrate the long-term persistence of antibodies following natural infection and the decrease in seropositivity that occurs after vaccination over time. This immunity waning may account for the higher susceptibility of adolescents and young adults to mumps. Therefore, the current vaccination program in the Czech Republic could be considered as less effective. It will be modified with the shifting of the second dose of vaccine from two years of age to the preschool age.

• Keywords
• Czech Republic, adults, antibodies, mumps, seroprevalence, vaccination program,
• MeSH
• Adult MeSH
• Disease Outbreaks prevention & control   MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Immunization Programs methods   MeSH
• Mumps blood   immunology   prevention & control   MeSH
• Antibodies, Viral blood   immunology   MeSH
• Surveys and Questionnaires MeSH
• Aged MeSH
• Seroepidemiologic Studies MeSH
• Measles immunology   prevention & control   MeSH
• Measles-Mumps-Rubella Vaccine immunology   MeSH
• Vaccination methods   MeSH
• Mumps virus immunology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• Antibodies, Viral MeSH
• Measles-Mumps-Rubella Vaccine MeSH