The Centers for Disease Control and Prevention (CDC) and Food and Drug Administration (FDA) said this decision was taken “out of an abundance of caution” while investigations are ongoing.
“This is important, in part, to ensure that the health care provider community is aware of the potential for these adverse events and can plan for proper recognition and management due to the unique treatment required with this type of blood clot,” a statement read.
“Right now, these adverse events appear to be extremely rare. 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.”
As of April 12, 6.8mln people had received the single-dose jab with six people experiencing a rare and severe type of blood clot.
These were all women between the ages of 18 and 48 and symptoms occurred 6 to 13 days after vaccination.
“We have been reviewing these cases with European health authorities. We have made the decision to proactively delay the rollout of our vaccine in Europe,” the pharma giant said on Tuesday.
“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.”
Treatment of this specific type of blood clot is different from the treatment that might typically be administered, the US authorities said.
Usually, an anticoagulant drug called heparin is used to treat blood clots but administration of heparin may be dangerous in this setting, so the patients had to receive alternative treatment.
The CDC and FDA added that people who have received the J&J vaccine who develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination should contact their health care provider.
Shares shed 3% to US$156.82 just before open.
–Adds J&J’s statement–