Covid vaccinations not tied to relapse, study finds

People living with multiple sclerosis (MS) have faced concerns about an increased risk of severe COVID-19 infection, along with worries about potential relapses following vaccination. However, a recent study brings some reassuring news. The research indicates that COVID-19 vaccination does not appear to increase the risk of relapse in most people with MS.

The study, which included 124,545 people with MS in France, found a slight increase in relapse risk following a booster dose, particularly in those with high MS activity. This was most noticeable among individuals who had experienced at least two relapses in the previous two years and were not taking any MS medications. However, the overall findings suggest that the vaccine does not heighten the risk of severe relapse.

Participants in the study had been living with MS for an average of 14 years and were monitored for 45 days after receiving a COVID-19 vaccine, as vaccine-related relapses typically occur within 28 days of vaccination. During this period, 102,524 participants, or 82%, received at least one dose of a COVID-19 vaccine, with 95% receiving a second dose and 59% receiving a booster.

The vaccines administered included Pfizer BioNTech, Moderna, AstraZeneca, and Janssen. Researchers specifically looked for relapses requiring treatment with high-dose corticosteroids within 45 days of vaccination.

After accounting for various factors such as the time of year and the effects of disease-modifying therapies, the researchers found no increased risk of severe relapse after COVID-19 vaccination. In fact, the study revealed a small decrease in relapse risk following vaccination.

To further validate the results, the study compared individuals who experienced relapses with those who did not. Once again, they found no increased risk linked to vaccination, providing additional reassurance for people with MS considering COVID-19 vaccination.

“Our findings are reassuring that these vaccines can be used without any worry about the risk of relapse,” the researchers said. “The absence of such a risk is encouraging for people with MS that they may receive booster shots when needed, especially if booster shots are to be repeated in the future.

“Particular caution is needed for patients with the highest inflammatory activity, who should first receive disease-modifying treatment before their booster vaccination. People who were untreated and those with a highly active disease showed a small increased risk after the third vaccine dose. The risk was highest if both factors were combined,” they said.