Study summary: Patient-reported safety and tolerability of COVID-19 vaccines in persons with rare neuroimmunological diseases

In response to the COVID-19 pandemic, several vaccines were developed and distributed across the world. Some of these vaccines received FDA approval in the United States (Pfizer, Moderna, and Johnson & Johnson), and another vaccine was approved by the European Union (AstraZeneca). These vaccines were recommended by several expert committees for people with autoimmune diseases and for people who are immunocompromised; however, the clinical trials excluded most people with rare neuroimmune disorders, which was cause for concern among physicians and those diagnosed with one of these disorders.

Researchers Dr. Michael Levy, Dr. Itay Lotan, and Gabriela Romanow conducted an anonymous survey to report real-world safety data of the COVID-19 vaccine in persons with rare neuroimmune disorders. Participants were recruited from a closed Facebook group called “The NMO Clinic”. Of the 438 respondents, 55.3% had a diagnosis of neuromyelitis optica spectrum disorder (NMOSD), 22.6% had MOG antibody disease (MOGAD), 18% had transverse myelitis (TM), 2.5% had recurrent optic neuritis, 1.4% had acute disseminated encephalomyelitis (ADEM), and 0.3% had isolated optic neuritis. 27.4% of participants had associated comorbidities, and 80.1% of participants were being treated with immunotherapies, the most common of which was Rituximab.

Participants were asked whether they experienced immediate adverse events, like injection reactions, fever, or chills, following vaccination. The results showed that 31.5% of respondents reported immediate adverse events, the most common of which were reactions at the injection site, including pain, redness, and swelling, followed by headache, muscle pain, fatigue, fever, chills, and dizziness. Of those who reported immediate adverse events, the majority were less than 55 years old. Of the participants who were being treated with immunotherapies, 35.3% reported immediate adverse events, in comparison to 32.1% of participants who were not being treated with immunotherapies, and this difference was not statistically significant. The survey indicated 51.4% of the participants on immunotherapies were on B-cell depleting agents including rituximab, ocrelizumab, and inebilizumab, and 33.5% of these participants experienced immediate adverse reactions. Comparatively, 67.5% of participants receiving other immunotherapies reported immediate adverse reactions.

Participants were also asked whether they experienced new or worsening neurological symptoms following vaccination. Results showed 16.7% of participants reported new or worsening neurological symptoms after receiving the COVID-19 vaccine. Of these, the majority were women (80.8%) and were being treated with immunotherapies (72.6%). The most common neurological symptoms were sensory disturbances such as numbness, tingling, and itching sensations; increased pain; muscle weakness; gait instability; visual symptoms; and sphincteric problems. Of participants who experienced new or worsening neurological symptoms, 82.2% did not require any additional treatment, while 12.4% received corticosteroids (1 in conjunction with IVIG), 4.2% were treated with additional painkillers, and 1.4% were treated with anti-nausea medication. The majority (52.1%) of respondents with new or worsening neurological symptoms reported that their symptoms resolved within 1-3 days. No participants reported having an MRI-confirmed relapse following vaccination.

The researchers compared the safety data from Pfizer’s clinical study of the COVID-19 vaccine in the general population and found that the rate of adverse events was higher in the general population than in the rare neuroimmune population who participated in this study. A possible explanation for this is that the majority of participants in this study were being treated with immunotherapies, which may blunt the effect of the vaccine, in turn causing less severe adverse events. This was especially prevalent in participants who were being treated with B-cell depleting therapies such as Rituximab.

The low rate of new or worsening neurological symptoms following COVID-19 vaccination is similar to data from existing (non-live-attenuated) vaccines that were not associated with a higher risk of relapse in autoimmune diseases. The researchers note that data reported in this study may help to alleviate hesitancy in the rare neuroimmune population to receive the COVID-19 vaccine.

A limitation of this study was that the data were reported anonymously and could not be confirmed by reviewing medical records. Also, participants did not undergo a medical examination to evaluate their symptoms, and all data were patient-reported. Finally, the study may not be representative of the rare neuroimmune population as a whole, because factors such as socioeconomic status, ethnic background, and physical disability can affect access to social media and internet; however, characteristics such as majority female, age, and immunotherapy treatments are similar to other groups of participants of NMOSD studies that have been published.

The researchers conclude that the safety of COVID-19 vaccines in the rare neuroimmune disorder community seems favorable. The rate of adverse events following vaccination is similar to that of the general population, and the rate of new or worsening neurological symptoms is relatively low with most symptoms being mild, resolving quickly, and not requiring additional treatment. The data should be evaluated in further studies.