Reader Response: Acute Inflammatory Diseases of the Central Nervous System After SARS-CoV-2 Vaccination
Elias SSotirchos, Assistant Professor of Neurology, Johns Hopkins University School of Medicine
Submitted December 12, 2022
While it is plausible that the ChAdOx1S vaccine may rarely be associated with post-vaccine demyelinating events, including MOGAD, the current study’s conclusions are not supported by the data/analyses presented.1 Notably, the authors’ conclusion is not based on an increase in the annual incidence of MOGAD cases after the SARS-CoV2 vaccine roll-out compared to the prior year, but solely on a deviation of the seasonal distribution of MOGAD incidence from a uniform distribution. An equally (un)supported interpretation would be that vaccination exhibits a delayed protective effect from MOGAD, given the lower than expected number of cases in the latter months of the examined period. Furthermore, seasonal variation of attacks of demyelinating disease (including NMOSD, MS, ADEM, and optic neuritis) has been reported extensively in the literature, with a similar seasonal pattern to that reported in the post-vaccine period.2–5 While this was not observed in the pre-pandemic data reported by the authors, this finding is somewhat at odds with existing literature on the topic, and how pre-pandemic cases (including in an era preceding the recognition of MOGAD as a distinct disease entity) were identified and classified as “MOGAD-onset” is rather unclear. Overall, the lack of a markedly increased incidence of referral of MOGAD cases following rapid implementation of a mass vaccination program (n=29 vs n=24 the year prior) is somewhat reassuring, as a sizable number of excess cases would be expected if a strong causal relationship existed.
Disclosure
The author reports no relevant disclosures. Contact nnnjournal@neurology.org for full disclosures.
1. Francis AG, Elhadd K, Camera V, et al. Acute Inflammatory Diseases of the Central Nervous System After SARS-CoV-2 Vaccination. Neurol Neuroimmunol Neuroinflamm. 2023;10:e200063.
2. Jin Y, de Pedro-Cuesta J, Söderström M, Stawiarz L, Link H. Seasonal patterns in optic neuritis and multiple sclerosis: a meta-analysis. J Neurol Sci. 2000;181:56–64.
3. Dale RC, de Sousa C, Chong WK, Cox TCS, Harding B, Neville BGR. Acute disseminated encephalomyelitis, multiphasic disseminated encephalomyelitis and multiple sclerosis in children. Brain. 2000;123:2407–2422.
4. Spelman T, Gray O, Trojano M, et al. Seasonal variation of relapse rate in multiple sclerosis is latitude dependent. Annals of Neurology. 2014;76:880–890.
5. Qiu Y, Zhou Q, Du Q, et al. Seasonal variation in relapse of neuromyelitis optica spectrum disorders: A retrospective study in China. Journal of Neuroimmunology. 2020;347:577351.
While it is plausible that the ChAdOx1S vaccine may rarely be associated with post-vaccine demyelinating events, including MOGAD, the current study’s conclusions are not supported by the data/analyses presented.1 Notably, the authors’ conclusion is not based on an increase in the annual incidence of MOGAD cases after the SARS-CoV2 vaccine roll-out compared to the prior year, but solely on a deviation of the seasonal distribution of MOGAD incidence from a uniform distribution. An equally (un)supported interpretation would be that vaccination exhibits a delayed protective effect from MOGAD, given the lower than expected number of cases in the latter months of the examined period. Furthermore, seasonal variation of attacks of demyelinating disease (including NMOSD, MS, ADEM, and optic neuritis) has been reported extensively in the literature, with a similar seasonal pattern to that reported in the post-vaccine period.2–5 While this was not observed in the pre-pandemic data reported by the authors, this finding is somewhat at odds with existing literature on the topic, and how pre-pandemic cases (including in an era preceding the recognition of MOGAD as a distinct disease entity) were identified and classified as “MOGAD-onset” is rather unclear. Overall, the lack of a markedly increased incidence of referral of MOGAD cases following rapid implementation of a mass vaccination program (n=29 vs n=24 the year prior) is somewhat reassuring, as a sizable number of excess cases would be expected if a strong causal relationship existed.
Disclosure
The author reports no relevant disclosures. Contact nnnjournal@neurology.org for full disclosures.
1. Francis AG, Elhadd K, Camera V, et al. Acute Inflammatory Diseases of the Central Nervous System After SARS-CoV-2 Vaccination. Neurol Neuroimmunol Neuroinflamm. 2023;10:e200063.
2. Jin Y, de Pedro-Cuesta J, Söderström M, Stawiarz L, Link H. Seasonal patterns in optic neuritis and multiple sclerosis: a meta-analysis. J Neurol Sci. 2000;181:56–64.
3. Dale RC, de Sousa C, Chong WK, Cox TCS, Harding B, Neville BGR. Acute disseminated encephalomyelitis, multiphasic disseminated encephalomyelitis and multiple sclerosis in children. Brain. 2000;123:2407–2422.
4. Spelman T, Gray O, Trojano M, et al. Seasonal variation of relapse rate in multiple sclerosis is latitude dependent. Annals of Neurology. 2014;76:880–890.
5. Qiu Y, Zhou Q, Du Q, et al. Seasonal variation in relapse of neuromyelitis optica spectrum disorders: A retrospective study in China. Journal of Neuroimmunology. 2020;347:577351.