VMS063

The study aimed to assess the effects of a single-dose measles, mumps, and rubella (MMR) booster vaccination, without prior testing, on MMR immunity and infection among vulnerable healthcare personnel (HCP) 10 years after implementation in a highly vaccinated population.

We conducted a single-center, cross-sectional study to assess the MMR seroprevalence in HCP and health examinees enrolled from December 2021 through April 2023. Since 2013, the hospital has provided a single-dose MMR booster vaccine to HCP working in high-risk units and those born in or after 1981 (≤41 years of age). HCP who met the Taiwan CDC's operational criteria for measles immunity were exempted. MMR-specific IgG antibodies were measured, and detailed vaccination histories were obtained.

A total of 732 participants were enrolled, including 528 HCP and 204 health examinees. The median age was 43 years, and 74.6 % were female. The overall seroprevalence rates of measles, mumps, and rubella were 89.8 %, 91.0 % and 88.0 %, respectively. The measles seroprevalence rate was lowest among participants aged 31-40 years (80.4 % in HCP and 82.4 % in health examinees). In multivariable analysis, age was associated with measles seropositivity (per 1-year increase, aOR, 1.08; 95 % CI 1.04-1.12). Receiving MMR booster vaccination in adulthood was associated with seropositivity for measles (aOR, 2.77; 95 % CI, 1.46-5.24) and mumps (aOR, 2.39; 95 % CI, 1.23-4.65). No cases of measles acquisition or intra-hospital spread were identified among HCP during the past 10 years.

An MMR booster vaccination program is feasible and effective in maintaining high seropositivity rates for MMR, particularly among HCP at risk of waning immunity.

The Copenhagen School Health Record Register (CSHRR) includes health information from school examinations and is now updated with information on measles, mumps and rubella vaccines for the cohorts born from 1977 to 1994.

The aim of this study is to provide a comprehensive description and validation the newly digitised vaccine information in the CSHRR.

We describe the data collection and the newly digitalised information in the CSHRR. We investigate the extent to which the full CSHRR population is representative of Copenhagen and the entire Danish population. Furthermore, we explore how the registry information on vaccination uptake based on reimbursement data matches the vaccine information obtained from CSHRR for the period during which both data are available.

The CSHRR population matches closely the complete population of all schoolchildren in Copenhagen, and information on vaccine uptake in CSHRR matches with vaccine registry data for later cohorts. However, a sizable proportion of the immigrant children in the CSHRR have missing information on vaccination. Removing children who have had no additional immunisations enhances data quality.

The CSHRR covers a large share of the Danish population and includes detailed vaccine information. By linking the data to other registry data, the updated CSHRR is valuable resource for future research.