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There is a dilemma public health authorities face when it comes to disseminating information about COVID-19 vaccines. The goal here is to reassure as many people as possible that these vaccines are safe and potentially life-saving.

However, we live in an age of disinformation, in which any real (or imaginary) issue can be blown out of proportion, shared across social media, and generate genuine anxiety. This means public health officials are faced with a nearly impossible task: how do you acknowledge potential (and extremely rare) side effects of vaccines, without alarming the public and feeding into the narrative that vaccines are unsafe altogether? 

This is a fine balancing act indeed; recently, countries that have been too relaxed in their vaccination programs have seen a surge in COVID-19 cases. This is entirely preventable, but democracies additionally bear the burden of having to balance lives and liberty, a Rubik’s cube of a problem that occurs only about once in a generation. 

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However, sound medical data collection also means scientists cannot cherry-pick; they are obliged to follow the evidence wherever it leads. In the case of neuromyelitis optica spectrum disorder (NMOSD), its relationship with COVID-19 vaccination has been rather complicated. Let’s explore why.

Anecdotal Evidence 

A quick search through medical literature search engines reveals a number of articles that document NMOSD cases that occur in close proximity to COVID-19 vaccinations. The fact that scientists feel these cases warrant publication tells us the anxiety over vaccine-related exacerbations of NMOSD is very real. 

Read more about NMOSD diagnosis 

Let’s briefly examine a case report presented by Fujikawa et al. The case report involved a 46-year-old woman who developed NMOSD for the first time 10 days after receiving her first COVID-19 vaccine. Here are the highlights of the case study: 

Prior to receiving the SARS-Cov-2 mRNA-1273 vaccine, the patient was healthy and working as a teacher. Two days after receiving the vaccine, she developed shooting upper back pain that was described as 10/10 in severity. Cardiac causes of her pain were ruled out. 

She returned to the emergency department 3 days later, complaining of paresthesia distal to the T10 dermatome and bilateral upper- and lower-extremity weakness. She was prescribed prednisolone and a muscle relaxant. 

The next day, she returned again with partial urinary retention. Detailed investigations were carried out. The most significant finding is that “T2-weighted MRI of the cervical spine revealed increased, nonexpansile intramedullary signal involving the central gray matter at C6-T2 without enhancement, consistent with NMOSD,” the researchers wrote. 

The patient was prescribed vitamin B12, and later methylprednisolone 1g IV daily. The patient was determined well enough for discharge, and an outpatient visit a month later revealed that her bilateral lower-extremity muscle weakness had resolved. 

“Cases of post-vaccination NMOSD similar to ours have previously been reported. These include both de novo attacks and relapses,” Fujikawa and colleagues wrote. “Post-vaccination myelitis and other neurologic reactions are rare. Nonetheless, early recognition is important as treatment can sometimes curtail long-term disability.” 

A Possible Explanation 

Cai et al proposed a scientific explanation as to why COVID-19 vaccinations could plausibly increase the risk of NMOSD relapse, and it largely has to do with the immune system. The possible risk of COVID-19 vaccinations in the context of NMOSD relapses is that we still know very little about the safety, efficacy, and immunogenicity of vaccines in patients with NMOSD, particularly those who are undergoing immunotherapy.

“The potential impact between vaccination and autoimmunity is usually bidirectional. Vaccines can protect against infectious and some autoimmune diseases induced by infections, while vaccines could originally trigger autoimmune diseases,” Cai et al wrote. 

Read more about NMOSD etiology 

“According to previous studies, some vaccines may adversely impact the self-autoimmune system, primarily when an adjuvant exists,” Cai and colleagues wrote. “Therefore, analyzing and monitoring vaccination adverse effects related to autoimmunity is quite indispensable.” 

In other words, the immune system is largely a mystery, especially when there are competing factors involved, such as autoimmune disease and immunosuppressive therapy. This may explain why vaccine-related NMOSD relapses have been reported worldwide. However, these incidences remain extremely rare. As Cai et al conceded, “The vaccine-induced disease is extremely rare among most immunocompetent patients.”

A Cautionary Approach

To err on the side of caution, should COVID-19 vaccinations still be offered to known NMOSD patients? Yes.

However, there are a few different types of COVID-19 vaccines on offer, and Cai et al wrote, “all inactivated vaccines can be safely used in patients with altered immunity, whether [the] vaccine is an inactivated whole organism or a recombinant, subunit, split virus, toxoid, polysaccharide, or polyglycoprotein conjugate vaccine.” 

Reputable news sources have reported ad nauseam about the overwhelming advantages of receiving a COVID-19 vaccine, and they remain in place. The bulk of the problem with so-called COVID-19 side-effects is elegantly summarized by Cai et al: “it is still difficult to determine whether the interaction between vaccination and autoimmune disease is causal or coincidental.” The best approach for the medical community is to patiently await the results of ongoing studies and continue to practice vigilance in documenting possible side effects possibly induced by COVID-19 vaccines. 


Fujikawa P, Shah FA, Braford M, Patel K, Madey J. Neuromyelitis optica in a healthy female after severe acute respiratory syndrome coronavirus 2 mRNA-1273 vaccineCureus. Published online September 14, 2021. doi:10.7759/cureus.17961

Cai H, Zhou R, Jiang F, Zeng Q, Yang H. Vaccination in neuromyelitis optica spectrum disorders: Friend or enemy? Mult Scler Relat Disord. Published November 9, 2021. doi:10.1016/j.msard.2021.103394