COVID-19 Vaccine Reactions in People with MS Similar to General Population, Says New Society-Funded Study

Stuart Schlossman#COVID-19, MS Research Study and Reports

 November 17, 2021

Surveys of hundreds of people with MS enrolled in the iConquerMS network reveal that reactions to COVID-19 vaccine doses are similar to those experienced in the general population. People on certain disease-modifying therapies were less likely to experience reactions. This study adds to growing research on the safety of COVID-19 vaccination for people with MS.


  • People living with MS are seeking peace of mind on the safety and effectiveness of the COVID-19 vaccines. Research is underway to learn more about any specific medical impacts for people with MS receiving COVID-19 vaccinations. The National MS Society and the Accelerated Cures Project teamed up to gain insight into people’s personal experiences with the vaccines.
  • Between March and June 2021, participants in iConquerMS, an online people-powered research network initiated by the Accelerated Cure Project, answered surveys on reactions to COVID-19 vaccines, disease-modifying therapy use, and other factors. Most received the Pfizer-BioNTech vaccine (BNT162b2 ) or Moderna vaccine (mRNA-1273).
  • Among 719 people with MS who participated, 64% experienced a reaction after their first vaccine dose, and 17% had a severe reaction. Most common reactions were pain at injection site, fatigue, headache, and malaise (a general feeling of discomfort) – these are similar to those seen in the general population. People who were younger, female, had a previous COVID infection were more likely to have reactions.
  • Among 442 participants who reported receiving the second vaccine dose, 74% reported experiencing a reaction similar to those seen after the first dose, and 22% reported that they considered the reaction to be severe. People who were younger and had received the Moderna vaccine were more likely to have a reaction to the second dose.
  • People treated with alpha-4-integrin blockers (such as Tysabri) and sphingosine-1-phosphate receptor modulator (such as Gilenya or Mayzent) were less likely to have a severe reaction after the first shot. Those taking a sphingosine-1-phosphate receptor modulator or fumarate (such as Tecfidera or Vumerity) were less likely to have a reaction after the second shot.
  • The authors conclude that the results provide “a reassuring picture” for people with MS, and hope that the information addresses the concerns of those who remain hesitant to be vaccinated.
  • Research on the immune response to the vaccines in MS is underway.


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