Reports of Guillain–Barré syndrome exceeded the expected background for the Vaxzevria ChadOx1-S COVID-19 vaccine, but not for either of the mRNA vaccines on offer in Australia, a case series suggests.
The data was compiled via Victoria’s spontaneous surveillance system, SAFEVIC, and describes 41 cases of GBS reported after a COVID-19 vaccine in the state from February to November 2021.
Each was reviewed by a neurologist to confirm probable GBS diagnosis.
Of those, 38 cases were reported post-vaccination with the AstraZeneca ChadOx1-S vaccine and three after the Pfizer vaccine, Comirnaty BNT162b2.
The third vaccine available in that time Spikevax mRNA-1273, sponsored by Moderna, was linked with no GBS cases reported to the registry.
But only patients receiving the Vaxzevria ChadOx1-S vaccine were at higher risk, with a GBS incidence of 1.85 reports per 100,000 first doses, according to the case series described in the journal Vaccine (link here).
This was significantly higher than the expected rate of 0.39 hospital admissions per 100,000 adults within 42 days of vaccination, the author wrote.
Of the post-ChadOx1-S vaccine reports, the median age at vaccination was 66 years and median onset of symptoms was 14 days following immunisation. There was one death.
The authors stressed the TGA had identified 11 deaths linked to COVID-19 vaccination in total – all post-ChadOx1-S vaccine – including one additional case of GBS, one of immune thrombocytopenia and eight with vaccine induced thrombotic thrombocytopenia (VITT).