Updated April 13, 20214:50 PM
ET MARIA GODOY RICHARD HARRIS
Federal
health officials have called for a "pause" in the use of the Johnson
& Johnson vaccine after reports that six women who got the vaccine
developed blood clots afterward. Close to 7 million people have gotten this
vaccine in the U.S. to date.
The
Centers for Disease Control and Prevention says the blood clots are extremely
rare but that it is reviewing the cases. The agency says it expects this pause
to last for "a matter of days."
The
CDC's principal deputy director, Dr. Anne Schuchat, says the pause is intended "to
prepare the health care system to recognize and treat patients
appropriately."
So how
worried should you be about these rare cases? And how would you know if you
might be at risk? We have answers.
Who
is being affected by these blood clots?
The
clots that have been reported so far are in women between the ages of 18 and
48. Their symptoms emerged six to 13 days after vaccination. However, at a news
conference Tuesday, the acting commissioner of the Food and Drug
Administration, Janet Woodcock, said that at this point there's not enough
information to say whether any particular subgroup is more vulnerable.
The
CDC's Schuchat added that there are too few cases at this point to determine
what specific risk factors might predispose someone to developing these clots.
What
kind of blood clots are we talking about?
The FDA says the clots are a rare and severe type that
happens in the blood supply that drains the brain. It's called cerebral venous
sinus thrombosis, or CVST, and it is being seen in combination with low levels
of blood platelets (a condition called thrombocytopenia).
The symptoms
of CVST vary, but they can include headache, blurred vision,
fainting or loss of consciousness, loss of control over movement in part of the
body and seizures.
How
severe were the cases reported so far? Were any fatal?
The CDC
said Tuesday that among the six reported cases, one was fatal and one patient
is in critical condition.
NPR has
found a listing in the CDC's Vaccine Adverse Event Reporting System that
appears to be the description of the woman who died after getting the vaccine.
The report describes a 45-year-old woman in Virginia
who got a Johnson & Johnson shot in early March. A week after getting the
shot, she got a severe headache and ended up going to the hospital for it. She
had blood clotting and a low platelet count, and she died about two weeks after
getting the vaccine.
FDA
officials said Tuesday that their best guess at the moment is that these types
of reactions could be a rare autoimmune reaction. They emphasize that these
events are "extremely rare."
What
action has the FDA taken with regard to the Johnson & Johnson vaccine?
The FDA
has suggested that health care providers pause the use of the vaccine while the
side effects are being studied. However, providers are not prohibited from
using the vaccine if they feel the benefits to an individual patient outweigh
the risks. The government is convening an expert review panel that will hold a
public meeting Wednesday. Officials hope to resolve these safety questions in a
matter of days.
If
you got the Johnson & Johnson vaccine recently, should you be on the
lookout for symptoms? Which ones?
If you
got your shot more than a month ago, your risk of developing these clots is
"very low at this time," Schuchat says. The CDC and
FDA say these events appear to occur one week to "not longer than three
weeks" after vaccination.
Schuchat
says people who got the vaccine within the last couple of weeks should watch
for severe headache, abdominal pain, leg pain or shortness of breath. If you
develop these symptoms, seek medical treatment — with your doctor or by going
to an urgent care clinic or the emergency room — and let doctors know you were
recently vaccinated.
Officials
note that these symptoms are different from the mild flu-like symptoms, such as
fever and mild headaches, that you might experience a few days after getting
the vaccine.
Dr. Peter
Marks, the director of the Center for Biologics Evaluation and Research at the
FDA, adds, "It would be more important if someone reported to an emergency
room with a very severe headache or blood clots."
If you
got the vaccine very recently, "don't get an anxiety reaction," said
Dr. Anthony Fauci at a White House news conference Tuesday. "Because
remember it's less than 1 in a million. However, having said that, pay
attention." Fauci advises people to observe any symptoms that crop up,
especially a sudden, severe, headache that hits a week or two weeks after the
vaccination.
How
is this condition treated?
Health
officials emphasize that these clots should not be treated the way other clots
often are. Most importantly, Marks says doctors should avoid using heparin, a
standard blood-thinning treatment, because in these clots it "can cause
tremendous harm, or the outcome can be fatal."
But
there is no simple substitute. Treatment with alternate medications needs to be
individualized, doctors say, because these patients don't simply have blood
clots — they also have lower levels of platelets. And that can raise a person's
risk of increased heavy bleeding, because it makes it harder for blood to clot.
Marks
at the FDA says that ideally, patients with this rare condition should be
referred to physicians experienced in treating blood clots. The need for this
specialized treatment is one reason the CDC and the FDA saw an urgent need to
get the word out about this rare combination of side effects.
Do
doctors know what is causing these clotting events? What's the mechanism?
Scientists
have a working hypothesis but don't have complete answers. Marks at the FDA
says the leading hypothesis is that, on rare occasions, the vaccine can trigger
an undesirable immune response. So instead of simply prompting the body to
produce antibodies that protect against the coronavirus, people also generate
antibodies that affect blood platelets. That could explain why they are
depleted among people with this rare condition.
Researchers
in Europe noted this phenomenon among people who suffered
similar side effects after receiving the AstraZeneca vaccine.
Is
this happening with other vaccines too?
It's
not happening with the other vaccines authorized for use in the U.S. — the
Moderna and Pfizer-BioNTech vaccines — according to the FDA. Those vaccines are
based on a different technology, called mRNA, while the Johnson & Johnson
vaccine uses what's called viral vector technology.
However,
it has side effects similar to those seen with the AstraZeneca vaccine, which
is not approved for use in the U.S. but is used widely in other parts of the
world. Like the J&J vaccine, the AstraZeneca vaccine uses a modified virus
to activate the immune system's response.
Health
officials say the blood-clotting side effects of the AstraZeneca vaccine appear
to be more frequent than what has been reported for the J&J vaccine. One
estimate is they affect one person out of every 100,000 vaccines. So far for
the J&J vaccine, this condition has been identified in about 1 in a million
people, though health officials say there may be a small number of cases that
haven't yet been reported.
How
will this affect vaccine distribution?
The
White House said it expects no significant impact on its vaccination plan
because most of the vaccines used in the U.S. come from Pfizer and Moderna.
"This
announcement will not have a significant impact on our vaccination
plan," said Jeff Zients, the White House's COVID-19 response
coordinator. "Johnson & Johnson vaccine makes up less than 5 percent
of the recorded shots in arms in the United States to date."
Americans
scheduled for a J&J vaccine will be quickly rescheduled to receive a Pfizer
or Moderna vaccine, Zients said.
Deborah
Franklin and Pien Huang contributed to this report.
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