WASHINGTON — The United States' top health agencies announced on April 13 that they recommend a "pause" of single-dose Johnson & Johnson COVID-19 vaccines from being administered as they investigate "extremely rare" blood clot cases.
Centers for Disease Control (CDC) and Prevention and the Food and Drug Administration (FDA) said the clots occurred in six women about 6 to 13 days after they were vaccinated, and that all six of the cases included women between 18 and 48.
The agencies said the clots are also known as cerebral venous sinus thrombosis (CVST), where clots occurred in veins that drain blood from the brain. As of April 14th there is no evidence of a causal relationship between the vaccine and CVST.
New decisions mean new questions, and the Verify team is here to bring you the facts.
QUESTION: Is the risk of getting blood clots from COVID-19 higher than the risk from a Johnson & Johnson vaccine?
- Dr. Panagis Galiatsatos — Physician of Pulmonary and Critical Care Medicine and faculty member of the post-COVID-19 Clinic at Johns Hopkins University
- Dr. William Moss — Executive Director at the International Vaccine Access Center at Johns Hopkins University
- CDC & FDA — joint statement and media briefing
Currently, only six women have been identified as having these CVST blood clots following Johnson & Johnson vaccination.
That’s out of almost 7 million Americans total who have taken the J & J shot.
"Right now, these adverse events appear to be extremely rare," the CDC and FDA said in a joint statement. Still, the agencies are recommending a pause "out of an abundance of caution."
So, is the risk of getting blood clots from COVID-19 higher than the risk from a Johnson & Johnson vaccine?
Our Verify researchers brought that question to two Johns Hopkins University experts.
"So if that number six is all the cases, then we're talking about, you know, one in a million, it's possible that there are more cases that will turn up in the coming days," Dr. William Moss said. "Now with COVID-19, it's a little more difficult to find a comparable number, but what we can say is that the risk of blood clots is much higher, certainly, in individuals who are hospitalized and have severe COVID."
He continued: "There have been reports that there may be as many as a third, sometimes even a half of people who are in intensive care with COVID-19 will have evidence of blood clots."
As for the rate of patients with asymptomatic or mild COVID-19 developing blood clots, Moss said we don't know for sure how frequent that is.
Dr. Panagis Galiatsatos emphasized that those with severe COVID have a much higher risk of clotting than what we've seen so far with the J&J vaccine.
"The overall risk for COVID-19 is about 20%-21%," Dr. Galiatsatos said citing a recent Lancet study. "But the worse your COVID-19 is, say that you're sick enough land in an intensive care unit, the probability of developing a blood clot is about 31%."
And some studies say the risk is even higher.
A study published in the Journal of Vascular Surgery in January puts the risk of developing a deep thigh blood clot at between 21% and 69%.
So we can Verify that based on what we know right now, the risk of blood clotting from COVID is much higher than from the Johnson & Johnson vaccine.
HOW TO ASK MORE VACCINE QUESTIONS: Have questions? Text the Verify team at 202-895-5599 or shoot us an email at VERIFY@WUSA9.COM. You can also fill out the contact form below which goes straight to the Verify team.