By Peter Loftus
U.S. health authorities recommended a pause in the use of
Johnson & Johnson's Covid-19 vaccine in order to investigate
rare but severe cases of blood clots.
The U.S. Food and Drug Administration and the U.S. Centers for
Disease Control and Prevention announced the move Tuesday, after
finding that six women between the ages of 18 and 48 years who got
the vaccine had developed blood clots. More than 6.8 million doses
have been administered in the U.S., the agencies said.
A panel of outside experts will meet Wednesday to review the
matter for the CDC, while the FDA will also conduct an
The FDA said it was recommending a pause in the use of the
J&J vaccine "out of an abundance of caution."
J&J said Tuesday it is aware of an extremely rare disorder
involving people with blood clots in combination with low platelets
in a small number of people who received its vaccine. J&J said
it is working with health authorities and medical experts.
The company also said it has decided to delay the rollout of its
vaccine in Europe, which had been planned for later this month.
The halt comes at a dangerous time during the pandemic, as
health authorities race to vaccinate as many people as possible
before variants develop that can evade the shots. Among the biggest
hurdles is overcoming hesitancy to get vaccinated.
The specter of blood clots could add to concerns about the
safety of the shots, though vaccines from Pfizer Inc. and its
partner BioNTech SE and from Moderna Inc. have proven relatively
safe so far.
Pause of the J&J's vaccine use could hurt some vaccination
efforts in the U.S., especially in areas that lacked the special
freezers required to store the Pfizer-BioNTech and Moderna
Yet the impact could be limited because Pfizer and Moderna have
been ramping up production as they gained more experience making
the shots and expanded their manufacturing capabilities.
The U.S. has an abundant supply of the Pfizer-BioNTech and
Moderna vaccines, a Health and Human Services Department official
said. The J&J vaccine won't be given at federally-run
vaccination sites, the official said.
Some states and vaccine providers quickly made alternative plans
in response to the call for a pause by federal health officials.
New York Gov. Andrew Cuomo tweeted that state-run mass vaccination
clinics would offer the Pfizer-BioNTech vaccine in lieu of the
J&J vaccine to people with appointments Tuesday.
Separately, Australian health officials said Tuesday the country
has decided against using J&J's shot, after a panel of
scientific experts advising the government said it shouldn't buy
any more vaccines of its type.
European health authorities have been looking into the clotting
J&J said last week it was aware of a small number of cases
of clots after vaccination, and that there was no clear causal
relationship between them and the vaccine.
J&J's vaccine was the third authorized for use in the U.S.
It uses similar technology as a vaccine from AstraZeneca PLC and
the University of Oxford, not yet authorized in the U.S. that has
also been linked to rare cases of blood clots.
The J&J and AstraZeneca viral-vector vaccines contain a
virus that causes the common cold, but which has been rendered
harmless. That virus is engineered to include genetic instructions
that set off an immune response to protect people against the
The Pfizer and Moderna vaccines use a different technology,
called messenger RNA, to achieve the same goal.
J&J's vaccine is given in one dose, whereas the Pfizer and
Moderna shots are given as two doses, three or four weeks
In the case of J&J's shot, six women ages 18 to 48 developed
blood clots after taking the J&J vaccine, the FDA and CDC said.
The clots developed 6 to 13 days after vaccination. The women also
had in their blood low counts of platelets, which help with
Given the nature of the side effect, doctors shouldn't use the
normal course of clotting treatment, involving a drug called
heparin, the FDA and CDC said. "In this setting, administration of
heparin may be dangerous, and alternative treatments need to be
given," they said.
The agencies said people vaccinated with J&J's vaccine
should notify their doctor if they develop severe headache,
abdominal pain, leg pain, or shortness of breath within three weeks
Clots can be life-threatening, even fatal, if they choke off
blood and therefore oxygen flow to the brain or heart. The type of
blood clot seen in some people receiving the J&J vaccine was
called a cerebral venous sinus thrombosis, which can prevent blood
from draining out of the brain and can lead to a hemorrhage.
Like other Covid-19 vaccine makers, J&J, of New Brunswick,
N.J., developed its shot much more quickly than it usually takes to
develop a vaccine, given the urgency of the pandemic. The company
began work in early 2020 and started testing the vaccine in people
Certain types of blood clots were seen in a small number of
subjects in the large clinical trial of J&J's vaccine that
supported its authorization in late February. The FDA said there
wasn't enough evidence at the time to determine whether the vaccine
was causing the clots, but said it would monitor the situation.
J&J paused the large study of its vaccine in October because
one vaccine recipient had a type of blood clot called a transverse
sinus thrombosis resulting in a brain hemorrhage, according to an
FDA document. J&J investigated and found that it wasn't related
to the vaccine, and resumed the study.
J&J also has had problems manufacturing its vaccine. A batch
of the vaccine's main ingredient that was being made at a
contractor's plant in Baltimore was recently ruined by
contamination, and no doses were distributed from the batch. Health
regulators still haven't authorized the plant where the mishap
occurred, hurting J&J's ability to churn out more doses.
Mass vaccination clinics administering the J&J vaccine in
North Carolina, Colorado and Georgia have closed temporarily in
recent weeks after some people receiving the shot experienced
adverse effects. It wasn't immediately clear whether the vaccine
Earlier this month, U.K. health authorities recommended against
giving AstraZeneca's shot to people under 30 years after receiving
reports of rare but deadly blood clots. Countries including Canada
and Germany have also restricted use.
The link between the vaccine and the clotting incidents is still
unclear. Scientists in Germany and Norway said the vaccine may
cause an autoimmune reaction that leads to clots in the brain.
Write to Peter Loftus at email@example.com
(END) Dow Jones Newswires
April 13, 2021 10:02 ET (14:02 GMT)
Copyright (c) 2021 Dow Jones & Company, Inc.