TAMPA, Fla. - Adverse reactions from COVID-19 vaccines are very rare, but after six people reported having blood clots after having the Johnson & Johnson vaccine in the U.S. and with AstraZeneca in Europe, the FDA has put a pause on administering the shots stateside.
Tuesday the U.S. government said six women developed clots out of 6.8 million people who got the Johnson & Johnson shot.
"There’s no study we can do that will include 6.8 million people and that’s why I think in a way this speaks to the safety of the process. We’ve had a safe process because we’re not finding a common severe reaction after the studies are done," said Dr. Kartik Cherabuddi, an epidemiologist and associate professor of infectious diseases at the University of Florida.
Cherabuddi said the reaction is similar to clots reported after the AstraZeneca vaccine in Europe.
"It’s a rare thing that’s happening, but that’s the mechanism that’s responsible. We don’t entirely know what’s triggering that," said Cherabuddi.
Virologist Dr. Michael Teng with USF Health said it underscores why scientists need to know how the public does with any vaccine, especially with severe reactions. University of South Florida researchers are part of a national clinical trial on allergic reactions. The National Institutes of Health is looking at effects from Pfizer and Moderna.
"The NIH wants to study this particular hypersensitivity reaction. What we’ve been seeing just in general from the hundreds of millions of doses that have been rolled out from the Pfizer and Moderna vaccines is that these events are pretty rare," said Dr. Teng.
For perspective, public health experts said you’ll stand a higher chance of getting a blood clot from the actual virus not from the vaccine. So scientists said it’s important to share how you doing after the shot.
"If there’s something weird that happens, we need to know about it. We need to study it and see if it really is related to the vaccine or not," said Teng.
A Centers for Disease Control advisory committee is expected to talk about the Johnson & Johnson blood clot reports Wednesday. Public health leaders encourage people who get the vaccine to report how they are feeling through the CDC’s vaccine reporting app.