Maryland pauses use of Johnson & Johnson COVID vaccine as CDC, FDA study six reports of blood clots

Vaccination sites in Maryland will pause the use of the Johnson & Johnson COVID-19 vaccine as federal government officials review six reported cases of an extremely rare and severe type of blood clot found in recipients of the immunization.

The cases are out of more than 6.8 million Americans who received that vaccine, but federal officials said Tuesday that they will determine whether the vaccine can be safely used and how.


“COVID-19 vaccine safety is a top priority for the federal government, and we take all reports of health problems following COVID-19 vaccination very seriously,” the U.S. Food and Drug Administration and the U.S. Centers for Disease Control and Prevention said in a joint statement.

The six vaccine recipients reportedly experienced a type of blood clot known as called cerebral venous sinus thrombosis, or CVST. It was accompanied by low blood platelet levels. The six cases were found in women 18 to 48 years old, and all experienced symptoms within 13 days after injection, federal officials said.


They said people who have received the Johnson & Johnson vaccine who develop a severe headache, abdominal pain, leg pain or shortness of breath within three weeks after vaccination should contact their health care provider.

In Maryland, 173,534 people have received the Johnson & Johnson vaccine. That’s out of more than 3.5 million shots, with the bulk getting Pfizer/BioNTech and Moderna vaccines.

Gov. Larry Hogan said Tuesday that none of the cases were in Maryland, and the state has just a few thousands doses of the vaccine on hand, which will be preserved.

He said officials were able to make adjustments Tuesday after calls with federal officials, shutting the FEMA mobile sites and discontinuing the walk-up line at the Hagerstown mass vaccination site. Some pharmacies and physicians may have to postpone shots and refer patients to mass sites.

“It hasn’t really had a dramatic impact on us,” Hogan said. “But it’s something we’re watching very carefully. We want to make sure everybody’s safe. But we’re going to move forward big time on the other two vaccines.”

Federal health officials said during a news conference Tuesday that the Johnson & Johnson vaccine doses represent only about 5%, or nearly 7 million, pf shots administered nationally. There have been no issues found with the other vaccines, which use different technology, and White House officials said vaccine supply is sufficient to continue the pace of 3 million doses administered daily.

Still, because of the dangers from the coronavirus pandemic, every dose is needed, and officials will move quickly to evaluate the cases and ensure that doctors know how to spot, treat and report cases of clotting. Dr. Janet Woodcock, the acting FDA commissioner, said she expected the pause to last for just days.

Responding to questions about undermining trust in vaccines over so few cases, officials said a lack of transparency also could erode public trust.


“We are committed to safety and transparency and expeditiously learning as much as we can so further steps can be taken,” said Dr. Anne Schuchat, CDC principal deputy director.

The CVST clotting occurs when a blood clot forms in the brain and leads to hemorrhages. The symptoms are similar to those of strokes, such as headache, blurred vision, loss of mobility, seizures or fainting. Typically, blood clots are treated with anticoagulants, or blood thinners.

On Wednesday, a CDC advisory panel will review the cases and make recommendations about the vaccine’s use. The panel is unlikely to advise against using the vaccine. Rather, members could recommend who should receive the vaccine under what circumstances, said Dr. Wilbur Chen, a member of the CDC’s Advisory Committee on Immunization Practices.

Detecting a rare side effect after a vaccine is widely used isn’t unusual, Chen said. Trials test tens of thousands of people, compared with millions in the public, said Chen, chief of the adult clinical studies section at the University of Maryland School of Medicine’s Center for Vaccine Development and Global Health.

Chen said publicly reporting and reviewing the reactions “shows we have nothing to hide. We’ve been going through this process for decades. It engenders trust in the way we make decisions.”

European countries already are considering avoiding the vaccine’s use in females, a move the United States could consider, said Andrew Pekosz, a vaccine researcher and Johns Hopkins Bloomberg School of Public Health professor of molecular microbiology and immunology. He and a colleague once published a paper suggesting that uptake of vaccines could be improved if they were matched by sex to increase protections and reduce reactions.


Pekosz also said the clotting syndrome isn’t unexpected, as studies of other adenovirus-based vaccines, including the AstraZeneca and Sputnick COVID vaccines, have shown it’s a possible reaction, though the cause is unclear. In these vaccines, the common adenovirus is used to deliver genetic code to spur an immune response in people.

He supported the pause to investigate the rare cases, though he feared the “far-reaching” implications.

“I’ve already heard people saying they don’t want the J&J shot because of this and that is not the kind of thinking we need during a time when we should be increasing vaccinations,” Pekosz said. “The risk of severe disease from COVID is far, far greater than the risk of this blood clot syndrome.”

Jeffrey Kahn, director of the Hopkins Berman Institute of Bioethics, said the situation may now require offering people a choice of vaccines, which is possible as supplies grow. Otherwise, people may choose not to be vaccinated, which could prolong the pandemic.

Some people will never be comfortable with the Johnson & Johnson vaccine, but others will prefer the one-dose vaccine if officials deem it safe, particularly for certain groups, he said. In some cases, officials may need to consider if one dose of the two-dose Pfizer or Moderna vaccine is sufficient.

“We’ve gotten to this pause and there will be new information to factor into decision-making,” he said. “It respects people to allow them to choose when there is a choice to be had.”


For now, choice will be curtailed as vaccine providers say they would comply with state directives.

The Baltimore City Health Department said Johnson & Johnson represents a small fraction of its inventory, with a majority made up by Moderna, and halting use would not significantly affect operations.

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Montgomery County Health officials said they would swap Pfizer for Johnson & Johnson at the mass vaccination clinic in Germantown, the only place it’s available in the county.

At Hagerstown’s mass vaccination clinic, officials said they would also switch to the Pfizer vaccine, and would be able to honor all appointments made at least for Tuesday.

Kevin Lindamood, president and CEO of Health Care for the Homeless in Baltimore, recently decided to use only the Johnson & Johnson vaccine because of the ease of the one-dose regimen for those experiencing homelessness or living in shelters but will switch back to Moderna until federal officials provide more guidance.

The state has received relatively low levels of Johnson & Johnson vaccine this week and the week before as the company faces production delays. Millions of vaccine doses made at an East Baltimore plant it hired to make the vaccine had to be destroyed after the company determined the batch did not meet quality standards.


The facility, run by Gaithersburg-based Emergent BioSolutions, has not received emergency authorization from the FDA, and federal officials told The Baltimore Sun that supply of the vaccine will remain low until the plant meets federal standards. FDA documents show a range of quality control problems.

All of the doses already used in the United States came from Europe.

Johnson & Johnson has assumed control of the plant, and vaccine maker AstraZeneca has stopped its production line there. That vaccine has not yet been authorized in the United States.

For the record

This article has been updated to more accurately reflect Andrew Pekosz's title at Johns Hopkins. He's with the Bloomberg School of Public Health.