A rare variant of Guillain-Barré syndrome (GBS) may be linked to the Oxford-AstraZeneca Vaxzevria COVID-19 vaccine, according to UK neurologists.

Dr Guendalina Beatrice Bonifacio and colleagues at the Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, highlight what they say are five “remarkably similar” cases of bifacial weakness with paraesthesia (BFP), which developed up to 12 days post COVID-19 vaccination.

The patients, aged 43–71, had “phenotypic features of severe diplegia and paraesthesia”, “consistently high cerebrospinal fluid protein levels, bilateral facial nerve enhancement on MRI imaging and electrodiagnostics showing demyelination”, the neurologists said in a  letter published in the Journal of Neurology, Neurosurgery & Psychiatry

Respiratory muscles weren’t affected and most patients had a “favourable prognosis”, with “good response to intravenous immunoglobulin or spontaneous improvement”.

The cases of the rare GBS variant all occurred in the local Wessex area within a three month period, where typically they would see only one of two cases of classic GBS in a year.

The variant’s relatively high incidence, homogenous presentation and appearance within two weeks of vaccination “is suggestive of an aetiological link”, they said.

“Although a mild phenotype, early recognition and diagnosis may help prevent complications like falls and provide opportunity for early specialist rehabilitation,” they wrote.

Their article noted that viral infections and vaccines, such as those of influenza, are known to increase GBS risk and are thought to trigger an immune response that leads to peripheral nerve demyelination or axonal damage.

“Post-vaccination GBS remains rare and with COVID-19 claiming approximately 4 million deaths worldwide to date, vaccination against COVID-19 remains a global health priority,” the letter concluded.

The Melbourne Vaccination Eduction Centre estimates that GBS typically affects two in every 100,000 people per year.

The TGA is currently investigating over 50 suspected GBS cases associated with the AstraZeneca vaccine, however, a causal link has yet to be confirmed in Australia or overseas, the TGA’s 8 July safety report said.