Rare Spinal Cord Condition Flagged as Potential Adverse Effect of COVID-19 Vaccines: EU Drug Regulator

A dose of the AstraZeneca COVID-19 vaccine in a file photograph. Louai Beshara/AFP via Getty Images

The European Union’s drug regulator has indicated that a change to the product information for COVID-19 vaccines from AstraZeneca and Johnson & Johnson has been recommended to include a warning of a rare spinal cord condition called transverse myelitis.

TM is a rare condition that involves inflammation of one or both sides of the spinal cord. Symptoms can include weakness in the limbs, and tingling, numbness, pain or loss of pain sensation, or issues with bladder and bowel function.

The Pharmacovigilance and Risk Assessment Committee (PRAC), the European Medicines Agency’s (EMA) committee that assesses the safety of human medicines, recommended the change on Jan. 14 after concluding that a causal link between the two vaccines and TM is “at least a reasonable possibility.”

It recommends changing the product information for the COVID-19 shots—AstraZeneca’s Vaxzevria and Johnson & Johnson’s Janssen–to include a warning of “very rare cases of transverse myelitis (TM) reported following vaccination.” TM will also be added as an adverse reaction with an unknown frequency to the vaccine profile.

A vial of Johnson & Johnson's COVID-19 vaccine sits at a vaccination clinic in Los Angeles, Calif., on Dec. 15, 2021. Frederic J. Brown/AFP via Getty Images

The committee, over three days of meetings, reviewed information on globally reported cases for both vaccines, including data from the scientific literature as well as information from the European database for suspected vaccine side effects.

The PRAC said it considered that a total of 38 TM cases were reported globally—25 with Vaxzevria, 13 with Janssen. “These numbers refer to suspected and not adjudicated cases of TM.” This is out of 1.391 billion doses for Vaxzevria and 33,584,049 doses for Janssen that have been estimated to have been administered globally, it said.

“Health care professionals should be alert to signs and symptoms of TM, allowing early diagnosis, supportive care, and treatment,” the EMA announced. “People receiving either of these vaccines are advised to seek immediate medical attention if they develop symptoms of the condition.”

The risk-benefit profile of both vaccines remains unchanged, the EMA noted.

In December 2021, the EMA recommended a booster dose of the Janssen vaccine to be considered at least two months after the first dose in people aged 18 and above.

The PRAC on Jan. 14 also recommended that the product information for AstraZeneca’s Vaxzevria be revised to note that fewer events of thrombosis with thrombocytopenia (TTS) have been reported after the second dose compared to the first. TTS is a rare and severe blood clotting with low platelets disorder.

It was added as a rare side effect to the Vaxzevria shot in June 2021. Data reported to the UK government up to Aug. 4, 2021, estimates an overall incidence of TTS of around 14.9 per million after first or unknown doses of Vaxzevria.

A study published in the journal Science Advances on Dec. 1, 2021, suggested that an adenovirus vector in AstraZeneca’s vaccine, if modified, could significantly reduce the threat of TTS.