At least six people have exhibited symptoms of cerebral venous sinus thrombosis within six and 13 days of receiving the vaccine, the CDC and FDA said. Johnson & Johnson will also delay the vaccine's rollout in Europe.
The CDC and FDA have called for a pause in the use of the Johnson & Johnson vaccine following reports of six cases in which a rare and severe type of blood clot was discovered.
On Tuesday, Dr. Anne Schuchat, the CDC's principal deputy director, and Dr. Peter Marks, the director of the FDA’s Center for Biologics Evaluation and Research, announced in a statement that six women, between the ages of 18 and 48, exhibited symptoms of cerebral venous sinus thrombosis (CVST) and showed signs of low levels of blood platelets within six and 13 days of receiving the vaccine. One has died, while one is currently in critical condition at a Nebraska hospital, per New York Times.
CVST occurs when a blood clot forms in the brain's venous sinuses. The clot prevents blood from draining out of the brain and can trigger a stroke. Physical symptoms can include headache, blurred vision, fainting or loss of consciousness, loss of movement control, seizures or a coma. According to John Hopkins Medicine, CVST affects about five people per one million each year.
Still, out of an abundance of caution, both the CDC and FDA said they are taking “all reports of health problems following Covid-19 vaccination very seriously,” adding in their joint statement that, “[The] 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.”
Agency officials urged any recipient of the Johnson & Johnson vaccine to contact their health care provider should they experience severe headache, abdominal pain, leg pain or shortness of breath within three weeks of getting their shot.
As of Monday, more than 6.8 million doses of the Johnson & Johnson vaccine have been administered. Following the release of the CDC and FDA's statement, the pharmaceutical company issued a statement of its own, reading, “We are aware of an extremely rare disorder involving people with blood clots in combination with low platelets in a small number of individuals who have received our Covid-19 vaccine…. We have been working closely with medical experts and health authorities, and we strongly support the open communication of this information to healthcare professionals and the public. The CDC and FDA have made information available about proper recognition and management due to the unique treatment required with this type of blood clot.”
While blood clots are normally treated with an anticoagulant drug called heparin, the CDC and FDA said that administering the drug in Johnson & Johnson vaccine recipients who are experiencing CVST may actually be dangerous. Instead, “alternative treatments need to be given,” the agencies said.
J&J also announced that they “have made the decision to proactively delay the rollout of our vaccine in Europe.”
To date, more than 560,000 Americans — or one in every 588 U.S. residents — have died from Covid-19.