COVID-19 may alter NMOSD and MS risk and appears to be related to genetic susceptibility, a systemic review indicates.
Multiple sclerosis (MS) is a common central nervous system (CNS) condition with axonal damage, and its pathogenesis is unclear, though much is known about its risk factors. On the other hand, neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder, and an antibody against aquaporin-4 (AQP4) is frequently detected in the condition.
The COVID-19 pandemic has been the first of its kind in the 21st century, causing millions of deaths. However, COVID-19 also causes many long-term complications, including CNS issues and an increased risk of MS and NMOSD. These issues occur both due to the immune response to the virus and the ensuing cytokine storm. This systemic review, published in the Revue Neurologique, explored the risk of NMOSD and MS following COVID-19 vaccination.
There Have Been Few Reports of NMOSD and MS Post-COVID-19 Vaccination
The study carried out systematic research on leading databases, such as PubMed, Scopus, Web of Science, and Embase, using relevant search terms. The research returned 954 studies on the topic, but only 12 studies reported NMOSD or MS incidence post-COVID-19 vaccination. Of the 12 studies included in the study, there were reports of a total of 19 cases of MS or NMOSD post-COVID-19 vaccination.
These cases occurred within a few days of the first or second vaccine dose. On average, patients reported symptoms within 7.5 (4.8) after the first dose and 15.1 (12.8) after the second dose. A total of 89.4% of the patients were treated with methylprednisolone infusion, and 26.3% received plasma exchange (PLEX). All of the patients recovered with treatment. Six of the eight NMOSD patients tested positive for AQP4.
Although rare, the study shows that there is still some risk of NMOSD or MS post-COVID-19 vaccination. Most likely, it occurs in genetically susceptible individuals. The risk was associated with both vector-based vaccines and inactivated vaccines. It most likely occurs due to molecular mimicry. Vaccines trigger not only cellular immunity but also cytokine production. Both factors might increase the risk of these disorders in certain individuals. Such issues have also been associated with other vaccines against viral agents like hepatitis B and A, yellow fever, influenza, polio, rabies, HBV, and more. There are also reports of some severe, life-threatening complications after these vaccines.
The Bottom Line
The study concluded that there is ample evidence that vaccines may alter the risk of these conditions. However, the study had some limitations as a very low number of cases have been reported, and thus the results cannot be generalized. Hence, more studies are justified on the topic.
Source:
Mirmosayyeb, O., Ghaffary, E. M., Vaheb, S., Pourkazemi, R., & Shaygannejad, V. (2023). Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) following COVID-19 vaccines: A systematic review. Revue Neurologique, 179(4), 265–281. https://doi.org/10.1016/j.neurol.2022.11.004
