WASHINGTON (AP) – US on Tuesday recommended a “pause” in the use of the Johnson & Johnson COVID-19 single-dose vaccine to investigate reports of rare but potentially dangerous blood clots, a development that could jeopardize deployment of vaccines worldwide.
The Centers for Disease Control and Prevention and the Food and Drug Administration announced that they were investigating unusual clots that occurred 6 to 13 days after vaccination. The FDA commissioner said she hoped the break would last a few days.
The clots occurred in the veins that drain blood from the brain and occurred along with the lower platelets, the fragments of blood that normally form clots. All six cases corresponded to women between 18 and 48 years of age. One person died and all cases are still being investigated.
In the United States, more than 6.8 million doses of the J&J vaccine have been administered, the vast majority without mild side effects.
Any slowdown in the spread of gunfire could have far-reaching implications for the global vaccination effort. The J&J vaccine had a particular promise for less affluent countries, as its single-dose regimen and relatively simple storage requirements would facilitate use in the developing world.
The FDA said the investigated cases look similar to unusual clots that European authorities say are possibly related to another COVID-19 vaccine that has not yet been eliminated in the United States from AstraZeneca. European regulators have stressed that the risk of AstraZeneca appears to be lower than the possibility of developing clots from birth control pills.
Federally administered mass vaccination sites will pause the use of J&J firing and states and other providers are expected to continue. The other two authorized vaccines, from Moderna and Pfizer, make up the large number of shots of COVID-19 administered in the US and are not affected by the break.
“I would like to emphasize that these events seem extremely rare. However, the safety of the COVID-19 vaccine is a priority, “FDA Acting Commissioner Janet Woodcock told a news conference.
A CDC committee will meet Wednesday to discuss the cases and the FDA has also launched an investigation into the cause of the clots and the low platelet count.
Authorities have not seen similar clots after using Pfizer or Moderna vaccines, said Dr. Anne Schuchat of the CDC.
FDA officials stressed that Tuesday’s action was not a warrant. Doctors and patients could still use the J&J vaccine if they decide that its benefits outweigh its risks for individual cases, Dr. Peter Marks said.
Agencies recommend that people who receive the J&J vaccine contact their doctor if they have severe headaches, abdominal pain, leg pain, or shortness of breath within three weeks.
J&J said in a statement that it was aware of the blood clot reports, but that no link had been established with its vaccine. The company also said it would delay the launch of the vaccine in Europe as a precaution.
U.S. health authorities warned doctors not to use a typical clot treatment, anticoagulant heparin. “In this context, heparin administration can be dangerous and alternative treatments need to be done,” the FDA and CDC said.
European authorities investigating the AstraZeneca cases have concluded that clots appear to resemble a very rare abnormal immune response that sometimes affects people treated with heparin, leading to a temporary clotting disorder.
Although it is not yet clear whether reports among J&J recipients are related, doctors would treat this type of unusual clots as if they were treating people who have a heparin reaction, with different types of anticoagulants, and sometimes with a antibody infusion, said Dr. a clot expert at the University of Michigan.
As authorities investigate whether the clots are actually related to the J&J vaccine, Barnes stressed that Americans should be vaccinated as soon as possible using the other two vaccines available, from Pfizer and Moderna.
“If you have the opportunity to get vaccinated there, we strongly encourage it. The risks of COVID are real and high,” Barnes said.
Jeff Zients, White House COVID-19 response coordinator, said 28 million doses of Pfizer and Moderna vaccines will be available to states this week, more than enough to keep pace with 3 million shots a day. of the nation despite the J&J pause.
Asked if the government was overreacting to six cases of more than 6 million vaccinations, Schuchat said the recommendations would come quickly.
Because these unusual clots require special treatment, “it was of the utmost importance to make the word known,” he said. “That said, the pandemic is pretty serious and cases are on the rise in many places and vaccination is critical.”
States and cities moved quickly to implement the pause. The New York State Commissioner of Health, Dr. Howard Zucker said people who make an appointment Tuesday for J&J vaccines at state-run mass vaccination clinics will get the Pfizer vaccine.
The city of Dallas had planned to start a vaccination program at home using the J&J vaccine for the elderly or at home. The city said it will pause the program until more guidance is released.
The J&J vaccine received emergency authorization from the FDA in late February with great encouragement. However, the shooting represents only a small fraction of the doses administered in the U.S. J&J has been affected by production delays and manufacturing errors at a Baltimore contractor’s plant.
Last week, the pharmacist took over the facility to increase production in hopes of fulfilling its commitment to the U.S. government to supply about 100 million doses by the end of May.
According to CDC data, only about 9 million doses of the company have been delivered to the states and are pending administration.
So far, concern about unusual blood clots has focused on the AstraZeneca vaccine, which has not yet received authorization in the US. Last week, European regulators said they found a possible link between the shootings and a very rare type of blood clot that occurs together. with low blood platelets, which seems to occur more in younger people.
The European Medicines Agency points out that the benefits of receiving the vaccine outweigh the risks for most people. But several countries have imposed limits on who can get the vaccine; Britain recommended that alternatives be offered to those under 30.
But the J&J and AstraZeneca vaccines are made with the same technology. Major COVID-19 vaccines train the body to recognize the ear protein that coats the outer surface of the coronavirus. But the J&J and AstraZeneca vaccines use a cold virus, called an adenovirus, to carry the ear gene to the body. J&J uses a human adenovirus to create its vaccine while AstraZeneca uses a version for chimpanzees.
U.S. stock markets initially fell on J&J news, but some indices rose slightly in the late hours of the morning. Shares of Johnson & Johnson fell nearly 3 percent, an unusually large decline for the drug giant, with more stocks changing hands in the first two hours than on an average day.
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Associated Press writers Emily Wagster Pettus, Karen Matthews, Jill Bleed and Linda A. Johnson contributed to this report.