EU regulator finds possible link between Johnson & Johnson COVID shot, blood clots

Box of Johnson & Johnson COVID-19 vaccines
A box of Johnson & Johnson COVID-19 vaccines in Budapest, Hungary.
(Szilard Koszticsak / MTI)

Experts at the agency that regulates drugs for the European Union said Tuesday that they found a “possible link” between the Johnson & Johnson COVID-19 vaccine and very rare blood clots after a small number of cases were reported in the U.S., but they confirmed that the vaccine’s benefits still outweighed the very small risks of recipients developing the unusual clots.

The European Medicines Agency said a warning about very unusual blood clots should be added to labels for Johnson & Johnson’s COVID-19 vaccine. The agency said these rare blood disorders should be considered as “very rare side effects of the vaccine.”

Last week, Johnson & Johnson halted its European rollout of its one-dose vaccine after the Food and Drug Administration recommended a pause in its use in the U.S. while the rare blood clot cases are examined. Officials identified six cases of the highly unusual blood clots among nearly 7 million people who were immunized with the shot in the U.S.


Johnson & Johnson advised European governments to store their doses until the EU drug regulator issued guidance on their use; widespread use of the shot in Europe has not yet started.

The delay was a further blow to vaccination efforts in the European Union, which have been plagued by supply shortages, logistical problems and concerns over unusual blood clots also in a small number of people who received the AstraZeneca COVID-19 vaccine. Experts worry that the temporary halt of the Johnson & Johnson shots could further shake vaccine confidence and complicate worldwide COVID-19 immunization efforts.

Last week, South Africa suspended its use of the vaccine in the wake of the U.S. pause, and countries including Italy, Romania, the Netherlands, Denmark and Croatia put their Johnson & Johnson doses into storage.

Dr. Anthony Fauci says the U.S. will likely move to resume Johnson & Johnson’s COVID-19 vaccine this week after reports of six rare blood clot cases.

The blood clots linked to the Johnson & Johnson vaccine are occurring in unusual parts of the body, such as veins that drain blood from the brain. Those patients also have abnormally low levels of blood platelets, a condition normally linked to bleeding, not clotting.

With the AstraZeneca vaccine, scientists in Norway and Germany have suggested that some people are experiencing an abnormal immune system response, forming antibodies that attack their own platelets.

It’s not yet clear if there might be a similar mechanism with the J&J vaccine. But both the Johnson & Johnson and AstraZeneca vaccines, as well as a Russian COVID-19 vaccine and one from China, are made with the same technology. They train the immune system to recognize the spike protein that coats the coronavirus. To do that, they use a cold virus, called an adenovirus, to carry the spike gene into the body.

“Suspicion is rising that these rare cases may be triggered by the adenovirus component of the AstraZeneca and Johnson & Johnson vaccines,” said Eleanor Riley, a professor of immunology and infectious diseases at the University of Edinburgh in Scotland.

Reports of blood clots among those who got Johnson & Johnson’s COVID-19 vaccine may make some recipients anxious. Here’s how to handle those feelings.

She said that while more data was needed, “it remains the case that for the vast majority of adults in Europe and the USA, the risks associated with contracting COVID-19 far, far outweigh any risk of being vaccinated.”

On Monday, World Health Organization Director-General Tedros Adhanom Ghebreyesus said more than 5 million new coronavirus cases were confirmed worldwide last week, the highest-ever number in a single week. He noted that cases and hospitalizations among younger people were “increasing at an alarming rate.”

The European Medicines Agency, which regulates drugs used in the 27 European Union member nations, said last month there was a “possible link” between the AstraZeneca vaccine and rare blood clots but said the benefits of vaccination far outweighed the risks of COVID-19. It noted that the risk is less than the blood clot risk that healthy women face from taking birth control pills.

The European Union ordered 200 million doses of the Johnson & Johnson shot for 2021, and EU officials had hoped the one-shot vaccine could be used both to boost the continent’s lagging vaccination rates and protect hard-to-reach populations, such as migrant workers and the homeless.

CORE, co-founded by Sean Penn, has launched a campaign to increase shots in communities of color hit hard by the pandemic.

Last month, the African Union announced that it had signed a deal to buy up to 400 million doses of the Johnson & Johnson vaccine. Johnson & Johnson also has a deal to supply up to 500 million doses to the U.N.-backed COVAX initiative that helps get vaccines to the world’s poor.

Any concerns about the Johnson & Johnson vaccine would be another unwelcome complication for COVAX and for the billions of people in developing countries depending on the program. COVAX recently was hit by supply issues after its biggest supplier, the Serum Institute of India, announced that it would delay exports of the AstraZeneca vaccine for several months because of a surge of cases on the subcontinent.