The University of Wisconsin-Madison paused Johnson & Johnson (Janssen) vaccine distribution following an April 13 advisory from the CDC and FDA.
Reports of six U.S. women suffering from the same form of blood clot led federal agencies to halt one-dose J&J vaccine distribution. This comes after the administration of nearly seven million doses in the U.S..
“All six cases occurred among women between the ages of 18 and 48, and symptoms occurred 6 to 13 days after vaccination,” said Director of the Center for Biologics Evaluation and Research Peter Marks M.D., PhD., in an FDA statement.
University Health Services at UW-Madison will follow federal guidance by temporarily ceasing J&J vaccine administration. The university has administered 595 J&J doses thus far, according to Director of News and Media Relations Meredith McGlone.
“This pause has no impact on the safety and ongoing administration of the Pfizer and Moderna vaccines,” said McGlone. “We continue to encourage students and employees to seek vaccination on and off campus — it remains the best way to protect yourself, your loved ones and your community from serious illness and death due to COVID-19.”
Pfizer and Moderna mRNA vaccines make up 96% of those distributed across the state of Wisconsin, said Jennifer Miller and Elizabeth Goodsitt in a Department of Health Services news release.
McGlone noted that the clotting reports are rare and that the J&J vaccine was generally proven safe and effective in its goal of protecting individuals against the severe effects of COVID-19.
J&J vaccinated individuals are not advised to take particular preventative actions, McGlone said. However, she advises that campus community members experiencing heightened side effects contact their health care providers.
“There is still a lot to learn about how the vaccine might cause the problems that occurred in the six patients, which included blood clots around the brain and low platelets, but they do appear to be very rare,” said DHS Chief Medical Officer Dr. Ryan Westergaard in a Wisconsin DHS news release. “For residents who have received the Johnson & Johnson vaccine, be in contact with your health care provider if you have a severe headache or new vision problems during the first two weeks after receiving the vaccine.”
In a DHS briefing Tuesday afternoon, Dr. Ryan Westergaard - an infectious disease expert for UW - said the blood clotting symptoms seen in the six patients are very similar to a condition known as heparin induced thrombocytopenia (HIT). HIT is a rare condition seen when patients have a dangerous reaction to the drug heparin, which can cause blood to clot and platelets to be severely decreased.
The six patients with symptoms from the J&J shot had no exposure to heparin, but because the disorder looks very similar Westergaard said the reaction is likely based on a very specific pathology.
“[The medical community] has identified this new illness that we didn't even know existed a month ago,” he said in the briefing. “While we try to fully characterize [the reaction], it’s very appropriate to pause administering the vaccine while the medical community catches up.”
Westergaard said very similar blood clotting was seen in the Oxford Astrazeneca vaccine trials in Europe, and that vaccine uses a similar vector to the J&J shot.
“It is in our best interest to pause so doctors can catch up to the problem, to learn how to avoid and treat it going forward,” he said.
Now, the FDA will investigate reports of the cerebral venous sinus thrombosis blood clot. The Advisory Committee on Immunization Practices met Wednesday under CDC guidance to analyze reports and the importance of these cases with respect to vaccine administration, according to the FDA statement.
“Federal agencies are doing the right thing by pausing use of the J&J vaccine until it can be determined whether the vaccine played a role in increasing risk for these events,” said McGlone. “Safety continues to be the number one priority in this vaccination effort.”
Update: This story was updated April 13 to add comments from Dr. Westergaard given in the April 13 Wisconsin DHS briefing.