US regulators have warned that Johnson and Johnson’s single-dose Covid vaccine has been linked to rare cases of Guillain-Barré syndrome.
The Food and Drug Administration updated the vaccine fact sheets after their monitoring system received 100 reports of the neurological disorder, 95 of which required hospitalisation.
More than 12 million doses of the vaccine have been delivered in the US and regulators said the data suggests an association, there is insufficient evidence to prove a causal relationship with the neurological condition.
The FDA did confirm that ‘no similar signal’ has been identified with either Moderna or Pfizer vaccines.
Johnson and Johnson’s single-dose vaccine (known as Janssen in Europe) was approved for use in the UK in May with 20 million doses secured.
The Government reduced its original Janssen order from 30 million doses due to the ‘unprecedented scale and pace’ of the UK vaccine rollout.
There has been no use of the vaccine yet with deliveries expected later this year and ministers suggesting at the time ‘it will play an important role in the months to come’.
A spokesperson for the Medicines and Healthcare Products Regulatory Agency (MHRA) said: ‘We are aware of the FDA’s warning on Guillain-Barré Syndrome following vaccination with the Janssen Covid-19 vaccine.
‘Patient safety is our highest priority and we continually review new safety information to ensure that the benefits of all Covid vaccines outweigh the risks and update product information where appropriate.’
A recent laboratory study reported that the Janssen vaccine may be less effective against the Delta variant potentially raising questions around whether a second dose may be needed.
Some European countries, including Ireland, Germany and Spain have been using the vaccine to immunise homeless people because the single dose means they do not have to be registered or return for another appointment.
It comes as UK patients aged under 40 are no longer routinely offered the Oxford/AstraZeneca Covid vaccine after it was linked to a rare blood clotting disorder.