U.S. health officials are recommending a pause in administering the single-shot Johnson & Johnson COVID-19 vaccine while they investigate cases of blood clots in six women.
So if you’ve already received the J&J vaccine, here’s what you should know.
The six people who experienced clots were all women between the ages of 18 and 48, with symptoms developing six to 13 days after they received the shot, officials said.
For now, federal distribution channels, including mass vaccination sites, will pause the use of the J&J shot — D.C, Maryland and Virginia all announced their intentions to do the same Tuesday.
The Centers for Disease Control and Prevention and the Food and Drug Administration recommend that people who were given the J&J vaccine should contact their doctor if they experience severe headache, abdominal pain, leg pain or shortness of breath within three weeks.
The CDC says side effects for any of the COVID-19 vaccines can include pain, redness or swelling at the injection site; chills; fever; nausea; headache; or muscle pain.
J&J said in a statement that it was aware of the reports of blood clots, but that no link to its vaccine had been established.
Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said the public should be aware of any symptoms after receiving the Johnson & Johnson vaccine.
“If someone had recently [received the vaccine] within days, I would tell them to just, first of all, don’t get an anxiety reaction because remember, it’s less than one in a million,” Fauci said.
“However, having said that, pay attention. Do you have symptoms? Headache? Do you have shortness of breath? Chest discomfort? Do you have anything that resembles a neurological syndrome? And obviously, if you have something as serious as a seizure … that’s pretty clear.
“But the manifestations of this are that headache is the very common component of it because the sinus thrombosis that they have is the draining of the blood in the brain, and it will cause enough symptomatology to make you notice it. Just tell people to just watch out for not feeling very well.”
Dr. Joshua Sharfstein, vice dean for Public Health Practice at the Johns Hopkins Bloomberg School of Public Health, said instances similar to those under investigation are very rare.
“What it looks like is this is a very, very rare complication that really might only happen in the first couple of weeks,” he said. “So I think it’s very low risk to anyone who’s gotten the Johnson & Johnson shot.”
Sharfstein also said the six reported cases are among nearly 7 million doses of the J&J vaccine that have been administered in the U.S.
He thinks one point of interest for investigators will likely be “the connection between the Johnson & Johnson vaccine and the AstraZeneca vaccine, which has not been authorized in this country.”
Both share the adenovirus vector as the way the vaccine delivers its virus protection.
“This kind of rare blood clot has been associated with the AstraZeneca vaccine,” Sharfstein said, “so I think a question is whether the adenovirus vector may be, in part, responsible for this.”
Sharfstein does not believe the pause will substantially hamper the COVID-19 vaccine supply in the U.S. in the short term, because the overwhelming majority of the U.S. vaccine supplies come from Pfizer-BioNTech and Moderna. Both are very different vaccines, and neither have been linked to this particular kind of blood clot, so they’re not affected by the pause.
The FDA said the CDC will convene a meeting of its Advisory Committee on Immunization Practices on Wednesday to further review these cases and assess their potential significance. The FDA will then review that analysis as it also investigates the cases.
The Associated Press contributed to this report.
- Sign up for WTOP alerts
- Latest coronavirus test results in DC, Maryland and Virginia
- Coronavirus vaccine FAQ: What you need to know
- Latest vaccination numbers in DC, Maryland and Virginia