The rollout of the Johnson & Johnson COVID vaccine across Europe has been delayed, while US officials have recommended a “pause” in the use of the jab as reports of blood clots are investigated.
The healthcare giant said on Tuesday it had “made the decision to proactively delay the rollout of our vaccine in Europe”.
It comes after officials from America’s Food and Drug Administration (FDA) and the Centres for Disease Control and Prevention (CDC) said they are looking into six reported cases “of a rare & severe type of blood clot” in women aged 18 to 48.
The symptoms occurred six to 13 days after they received the jab.
A total of 6.8 million doses of the single-shot Johnson & Johnson vaccine have been administered in the US.
The company said that “no clear causal link” has been found between their vaccine and the clots.
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“Right now, these adverse events appear to be extremely rare,” the FDA said in a statement on Twitter.
It said until the cases had been assessed for their potential significance, “we are recommending this pause”.
“This is important to ensure that the health care provider community is aware of the potential for these adverse events and can plan due to the unique treatment required with this type of blood clot,” it added.
The European Union approved the Johnson & Johnson vaccine last month, with the company committed to delivering at least 200 million doses to the bloc this year.
Of those, 55 million doses had been due between this month and the end of June.
The US review of the Johnson & Johnson jab comes following the recent concerns over the link between the Oxford-AstraZeneca vaccine and blood clots.
The UK has not approved the Johnson & Johnson vaccine for use, but 30 million doses have been ordered.
In the US, the distribution network run by the federal administration – which includes mass vaccination sites – will pause the use of the vaccine.
The vaccination efforts run by states and other providers are expected to follow soon.
Jeff Zients, the COVID-19 response coordinator at the White House, said the pause “will not have a significant impact on our vaccination plan”.
He said the Johnson & Johnson vaccine made up “less than 5%” of the total number of vaccine doses delivered in the US and stressed there was “more than enough supply” of alternative Pfizer and Moderna jabs to meet President Joe Biden’s target of giving 200 million vaccine doses by his 100th day in office.
“We are working now with our state and federal partners to get anyone scheduled for a J&J vaccine quickly rescheduled for a Pfizer or Moderna vaccine,” Mr Zients added.
People who have had the Johnson & Johnson shot and experience a severe headache, abdominal pain, leg pain, or shortness of breath within three weeks have been told to seek medical help.
“We are aware that thromboembolic events including those with thrombocytopenia have been reported with COVID-19 vaccines,” said Johnson & Johnson in a statement.
“At present, no clear causal relationship has been established between these rare events and the Janssen COVID-19 vaccine.”
A meeting of the CDC’s Advisory Committee on Immunisation Practices will take place on Wednesday to review the cases.
Findings from this review will be analysed by the FDA as they investigate the situation.
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The numbers behind the AstraZeneca blood clot risk
Analysis: Suspension ordered out of abundance of caution
By Thomas Moore, science correspondent
Unusual blood clots with a second vaccine – and intriguingly it uses the same ‘viral vector’ technology as the AstraZeneca shot.
It’s far too soon to say there is a causal link with the Johnson & Johnson jab, but the US regulators have recommended a pause in its rollout as a precaution.
Almost seven million have been given the vaccine – and there have been six cases of a “rare and severe” form of blood clot.
The European regulators are also investigating cases.
Blood clots happen naturally, so the Food and Drug Administration will have to look carefully at the cases.
There is hypervigilance at the moment because of the concern over the use of the AstraZeneca vaccine in younger people.
Both vaccines use another virus to carry genetic material for the COVID spike protein into the body.
The Johnson & Johnson – also known as Janssen – vaccine isn’t yet licensed in the UK, but 30 million doses are on order.