ABSTRACT
Background: The aim of this study was to determine the pooled prevalence of COVID-19 vaccination among people with multiple sclerosis (pwMS) compared to the general population in Croatia. Method(s): Data from all pwMS entered in the MS Base register until24.03.2022 were extracted including age, sex, MS phenotype, disease-modifying therapy (DMT), COVID-19 vaccine, and date of vaccination (1st, 2ndand/or 3rddose). Data on the general population of Croatia were obtained from the vaccination register of the Croatian Institute of Public Health. Result(s): 464 pwMS (317 females, with a median age of 38.1 years, disease duration of 6.1 years, EDSS 1.5) were included in the analysis. 386 (83.2%) pwMS had relapsing-remitting, 26 (5.6%) primary progressive, 19 (4.1%) secondary progressive phenotypes, and 16 (3.4%) clinically isolated syndrome. Fifty-six (12.1%) pwMS were treatment naive, 21 (4.5%) were not on DMT at the moment of the last visit, 134 (28.9%) were on injectable DMTs, 84 (18.1%) on 1stline oral DMTs, and 169 (36.4%) were on high efficacy DMTs. 295 (63.6%) pwMS were fully COVID-19 vaccinated compared to 59.7% of the general population (p=0.089). However, in the age groups, 20-24 and 35-39 significantly more pwMS received 2 doses compared to the general population (p=0.001 and p=0.03, respectively). Vaccinated pwMS were older (40.5 vs 37.6 years, p=0.01), had higher EDSS (2.0 vs 1.0, p=0.025), and longer disease duration (6.39 vs 5.35 years, p=0.02), were more likely to have progressive disease course (p=0.049) and on high efficacy DMTs (p=0.045) compared to unvaccinated pwMS.In a multivariable logistic regression model, there were no predictors for COVID-19 vaccination in pwMS. Conclusion(s): There was a similar prevalence of vaccinated individuals in pwMS and the general population. However, in younger age groups significantly more pwMS were vaccinated when compared to the general population.