Authors' objectives: To determine whether there is any evidence to support the (causal) association on the development of transverse myelitis post mRNA Covid-19 vaccination.

Authors' results and conclusions: Sixteen and 15 published studies were identified on initial searches. Upon examination of the titles and abstracts of these 31 identified studies, nine studies were thought to be relevant and were retrieved in full for further appraisals. Of the nine studies that were retrieved in full, six did not provide relevant data or were not relevant to the objective of this systematic review and will not be discussed further. Hence, three new studies were added to this systematic review updating the risk of having transverse myelitis post-mRNA Covid vaccines. A comprehensive, 2024 review (literature search date October 17, 2023) investigating adverse events related to the COVID-19 vaccines used in the United States, published by the US NASEM, concluded that with regard to transverse myelitis, at that time, there was inadequate evidence to accept or reject a causal relationship with, any available, Covid-19 vaccination. In our update to this 2024 US NASEM review on adverse events associated with Covid-19 vaccination, we identified three relevant primary studies, two of these studies did not identify any association between Covid-19 mRNA vaccination and development of TM while one study reporting a case of neurogenic bladder due to acute transverse myelitis in a post BNT162b2 vaccination patient. Given the available evidence, at present, there was inadequate evidence to accept a (causal) association between Covid-19 mRNA vaccination and the development of TM.

Authors' methods: A comprehensive and systematic literature search was conducted on October 17, 2023, in a report entitled “Evidence Review of the Adverse Effects of COVID-19 Vaccination and Intramuscular Vaccine Administration”. The current paper provides an update to the original and was conducted on October 23, 2024. The search was done on commercial medical literature where a combination of keywords was employed in this search. No limitation, such as on the date or language of publication was implemented in any of these searches. A manual search was also planned and conducted on the references of the articles that were retrieved in full.

Project Status: Completed

URL for project: https://www.worksafebc.com/en/about-us/research-services/evidence-based-medicine-and-systematic-reviews

Year Published: 2024

URL for published report: https://www.worksafebc.com/en/resources/health-care-providers/guides/causal-association-development-transverse-myelitis-post-mrna-covid-19-vaccination?lang=en

English language abstract: An English language summary is available

Publication Type: Mini HTA

Country: Canada

Organisation Name: WorkSafeBC

Contact Address: 6591 Westminster Highway, Richmond, BC, V7C 1C6 Canada. Tel: 604-231-8417; Fax: 604-279-7698

Contact Name: ebpg@worksafebc.com

Contact Email: ebpg@worksafebc.com

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