Covid-19 may be a risk factor for multiple sclerosis (MS). This has been shown by new research at Örebro University and Örebro University Hospital, Sweden.
“We saw a raised risk of MS among people who had severe Covid-19. However, only an extremely small number of people who had severe Covid-19 received a subsequent MS diagnosis,” says Scott Montgomery, professor in clinical epidemiology.
Scott Montgomery examined the records of all patients with Covid-19 that were admitted to hospital in Sweden between 2020 and 2022.
The results showed that nearly 26 per 100,000 patients with serious Covid-19 subsequently developed MS. This was more than double the risk than in those without a Covid-19 diagnosis.
“I want to make it clear that MS is an uncommon disease and very few people in this study had an MS diagnosis linked with Covid-19. Approximately 26 people with new-onset MS per 100,000 with serious Covid-19 is only 0.02%.”
Scott Montgomery suspects that the number who are diagnosed with MS following severe Covid-19 will increase over the years after the pandemic.
“It can take up to 10 to 20 years until an MS diagnosis following a relevant exposure to the brain or spinal cord. The extent to which serious Covid-19 is a cause of MS will become clearer in several years,” says Scott Montgomery.
He hopes that the research will result in earlier diagnosis of MS among those affected so they can be treated before development of more advanced disease.
The relationship between multiple sclerosis (MS) and mRNA COVID-19 vaccinations has been extensively studied through peer-reviewed research, revealing important insights about safety and efficacy.
Clinical Safety Data
A comprehensive meta-analysis of 14,755 MS patients who received 23,088 vaccine doses demonstrated that only 1.9% experienced relapses within approximately 20 days post-vaccination4. Transient neurological symptoms occurred in 4.8% of patients, while serious adverse events were extremely rare at 0.1%4.
Long-term Safety Evidence
A one-year longitudinal study confirmed that mRNA COVID-19 vaccination:
- Did not exacerbate existing autoimmune conditions
- Did not trigger new neural autoantibodies
- Produced robust immune responses in over 80% of patients that lasted at least 6 months1
Impact on Disease Activity
The annualized relapse rate (ARR) actually decreased after vaccination compared to pre-vaccination periods (0.09 vs 0.19)1. This provides strong evidence that mRNA vaccines do not increase disease activity in MS patients.
Treatment Considerations
Disease-modifying treatments (DMTs) can affect vaccine response:
- Anti-CD20 therapies and fingolimod may reduce antibody response
- Patients on anti-CD20 therapies can still develop T-cell responses despite reduced humoral immunity5
- Vaccination timing should be adjusted for patients on certain DMTs, with a 12-week delay recommended after anti-CD20 therapy administration5
Clinical Implications
The evidence strongly supports that mRNA COVID-19 vaccines are safe for MS patients, with benefits significantly outweighing potential risks. While rare cases of MS manifestation following vaccination have been reported, these are considered exceptional events2, and the overall safety profile remains excellent for the MS population.
