AUTHOR=Czarnowska Agata , Tarasiuk Joanna , Zajkowska Olga , Wnuk Marcin , Marona Monika , Nowak Klaudia , Słowik Agnieszka , Jamroz-Wiśniewska Anna , Rejdak Konrad , Lech Beata , Popiel Małgorzata , Rościszewska-Żukowska Iwona , Perenc Adam , Bartosik-Psujek Halina , Świderek-Matysiak Mariola , Siger Małgorzata , Ciach Agnieszka , Walczak Agata , Jurewicz Anna , Stasiołek Mariusz , Kania Karolina , Dyczkowska Klara , Kalinowska-Łyszczarz Alicja , Galus Weronika , Walawska-Hrycek Anna , Krzystanek Ewa , Chojdak-Łukasiewicz Justyna , Ubysz Jakub , Pokryszko-Dragan Anna , Kapica-Topczewska Katarzyna , Chorąży Monika , Bazylewicz Marcin , Mirończuk Anna , Kulikowska Joanna , Kochanowicz Jan , Białek Marta , Stolarz Małgorzata , Kubicka-Bączyk Katarzyna , Niedziela Natalia , Warmus Paweł , Adamczyk-Sowa Monika , Podlecka-Piçtowska Aleksandra , Nojszewska Monika , Zakrzewska-Pniewska Beata , Jasińska Elżbieta , Zaborski Jacek , Milewska-Jȩdrzejczak Marta , Zwiernik Jacek , Zwiernik Beata , Potemkowski Andrzej , Brola Waldemar , Kułakowska Alina 

TITLE=Analysis of Side Effects Following Vaccination Against COVID-19 Among Individuals With Multiple Sclerosis Treated With DMTs in Poland

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.913283

DOI=10.3389/fneur.2022.913283

ISSN=1664-2295

ABSTRACT=Background and objectives: Hesitancy towards COVID-19 vaccines is a major challenge for social health, especially in individuals with comorbid diseases. We conducted a large study of side effects following the COVID-19 vaccine among patients with multiple (MS) sclerosis treated with disease-modifying therapies (DMTs) and analyzed factors predisposing for particular adverse events. 
Methods: We gathered data of individuals with MS treated with DMTs from 19 Polish MS Centers, who reported at least one adverse event following COVID-19 vaccination. The information was obtained by neurologists using a questionnaire. The same questionnaire was used at all MS Centers. To assess the relevance of reported adverse events, we used Fisher’s exact test, t-test, U-Mann-Whitney test, and maximum likelihood estimates of the odds ratios. 
Results: A total of 1668 patients with MS and reports of adverse events after COVID-19 vaccination were finally included in the study. Besides one case marked as ‘red flag’, all adverse events were classified as mild. Pain at the injection site was the most common adverse event, with a greater frequency after the first dose. Pain at the injection site was significantly more frequent after the first dose among individuals with a lower disability (EDSS ≤2). The reported adverse events following immunization did not differ over sex. According to age, pain at the injection site was more common among individuals between 30 and 40 years old, only after the first vaccination dose. None of the DMTs predisposed for particular side effects. 
Conclusions: According to our findings, vaccination against COVID-19 among patients with MS treated with DMTs is safe. Our study can contribute to reducing hesitancy towards vaccination among patients with MS.