Federal health agencies will temporarily stop using Johnson & Johnson’s one-dose vaccine after six women developed blood clots, including one who died, according to officials and a new report Tuesday.
The Food and Drug Adminstration announced the pause, saying there’ve been a half-dozen reports of a “rare & severe type of blood clot” in patients who received the vaccine.
The clots were observed along with reduced platelet counts, making the usual treatment for blood clots — the blood thinner heparin — potentially “dangerous.”
“Right now, these adverse events appear to be extremely rare,” the agency tweeted in a joint statement with the Centers for Disease Control and Prevention.
Those affected were six women, between the ages of 18 and 48, who developed the clots within about two weeks of vaccination, the New York Times reported.
One died and a second in Nebraska was hospitalized in critical condition.
People who received the J&J vaccine who are experiencing severe headache, abdominal pain, leg pain or shortness of breath within three weeks after receiving the jab are advised to contact their health care provider.
The feds hope the pause will serve as a strong signal to states to do the same.
“We are recommending a pause in the use of this vaccine out of an abundance of caution,” the FDA said. “Treatment of this specific type of blood clot is different from the treatment that might typically be administered.”
In the US, 300,000 to 600,000 people a year develop blood clots, according CDC data cited by the Times, which reported that the particular clotting disorder that the J&J recipients developed, known as cerebral venous thrombosis, is extremely rare.
All of the women developed the condition within between six and 16 days of being inoculated, the paper reported, and experts are concerned that an immune system response triggered by the jab was the cause.
Nearly 7 million people in the US have gotten the J&J shot so far. About 9 million more doses have shipped to states, according to the CDC.
Federal distribution channels, including mass vaccination sites, will pause the use of the J&J vaccine, with states and other providers expected to follow.
The other two authorized vaccines in the US — Pfizer/BioNTech and Moderna — are not affected by the pause.
The CDC’s Advisory Committee on Immunization Practices will meet Wednesday to discuss the cases and the FDA has also launched an investigation.
The FDA added: “CDC will convene a meeting of the Advisory Committee on Immunization Practices (ACIP) on Wednesday to further review these cases and assess their potential significance. FDA will review that analysis as it also investigates these cases.
“Until that process is complete, 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 said.
While the move was described as a recommendation to health providers nationwide, the federal government will pause administration of the jab at all federally run vaccination sites, the Times reported.
The pause could significantly complicate US inoculation efforts as many states face a surge in new cases and seek to address vaccine hesitancy.
Regulators in other countries are concerned about a similar issue with another vaccine, developed by AstraZeneca and Oxford University researchers, according to the newspaper.
That concern has raised the number of anti-vaxxers, even though the AstraZeneca jab has not been approved for use in the US, he Times noted.
In the US, most of the vaccine supply comes from Pfizer/BioNTech and Moderna, which together deliver more than 23 million doses a week of their two-shot vaccines.
There have been no significant safety concerns about those inoculations.
The J&J vaccine received emergency use authorization from the FDA in late February amid hopes that its single dose and relatively simple storage requirements would speed vaccinations across the country.
But the jab only makes up a small fraction of the doses administered in the US as J&J has been plagued by production delays and manufacturing errors at the Baltimore plant of a contractor.
Last week, the company took over the facility to ramp up production in hopes of meeting its commitment to the federal government of providing about 100 million doses by the end of May.
Until now, concerns about blood clots have centered on the vaccine from AstraZeneca, which has not yet received US authorization.
Last week, European regulators said they found a possible link between the shots and a very rare type of blood clot that occurs together with low blood platelets, one that seems to affect younger people more.
Several countries have imposed limits on who can receive the AstraZeneca vaccine, including Britain, which recommended that people under 30 be offered alternatives.
The J&J and AstraZeneca vaccines are both made with the same technology.
The leading vaccines train the body to recognize the spike protein that coats the outer surface of the virus — but the J&J and AstraZeneca vaccines use a cold virus, called an adenovirus, to carry the spike gene into the body.
J&J uses a human adenovirus to create its vaccine while AstraZeneca uses a chimpanzee version.
With Post wires
