FDA restricts J&J COVID-19 vaccine due to risk of blood clots

U.S. regulators on Thursday severely restricted who could receive Johnson & Johnson’s COVID-19 vaccine due to the continued risk of rare but serious blood clots.

The Food and Drug Administration has said the vaccine should only be given to adults who cannot get another vaccine or specifically request the J&J vaccine. U.S. authorities have for months advised Americans starting COVID-19 vaccinations to use Pfizer or Moderna shots instead.

FDA officials said in a statement that they decided to restrict the J&J vaccine after re-evaluating data on the risk of life-threatening blood clots within two weeks of vaccination.

The J&J vaccine was originally considered an essential tool in the fight against the pandemic because it only required one shot. But the single-dose version was less effective than two doses of the Pfizer and Moderna vaccines.

In December, the Centers for Disease Control and Prevention recommended that Moderna and Pfizer vaccines be preferred over J&J due to safety concerns. Previously, US officials treated all three vaccines the same way, as each has been shown to provide strong protection.

But subsequent studies have consistently shown the lower efficacy of the J&J vaccine. And while the blood clots seen in the J&J shot are rare, officials say they still occur.

As of mid-March, federal scientists have identified 60 cases, including nine deaths. That’s one case of a blood clot in every 3.23 million J&J injections given, the FDA said on Thursday. The vaccine will carry a stronger warning about the potential “long-term and debilitating health consequences” of the side effect.

Under the new FDA guidelines, the J&J vaccine can still be given to people who have had a severe allergic reaction to one of the other vaccines and cannot get an extra dose. The agency said the J&J vaccine could also be an option for people who refuse to receive mRNA vaccines from Pfizer and Moderna and therefore would otherwise be left unvaccinated.

A J&J spokesperson said in an emailed statement, “The evidence continues to support a favorable benefit-risk profile for the Johnson & Johnson COVID-19 vaccine in adults compared to no vaccine.”

Despite the restriction, FDA head of vaccines Dr. Peter Marks said the J&J vaccine “still plays a role in the current pandemic response in the United States and around the world.”

The FDA based its decision on “our safety surveillance systems and our commitment to having science and data guide our decisions.”

Blood clotting problems first surfaced last spring with the J&J vaccine in the US, as well as with a similar vaccine made by AstraZeneca that is being used in other countries. At the time, U.S. regulators decided that the benefits of the single-shot J&J vaccine outweighed what was considered a very rare risk—provided the recipients were forewarned.

COVID-19 also causes fatal blood clots. But the type associated with the vaccine is different, as it is thought to be formed due to an uncontrolled immune response to the J&J and AstraZeneca vaccines due to the way they are made. It forms in unusual places, such as in the veins that carry blood away from the brain, and in patients with abnormally low levels of platelets that form clots. Symptoms of unusual clots include severe headaches a week or two after the J&J vaccination, rather than immediately, as well as abdominal pain and nausea.

The New Brunswick, NJ-based company announced last month that it does not expect a profit from the vaccine this year and is suspending sales forecasts.

The introduction of the company’s vaccine was hampered by a number of problems, including manufacturing problems at the Baltimore plant, which forced J&J to import millions of doses from overseas.

In addition, regulators have added warnings for blood clots and a rare neurological reaction called Guillain-Barré syndrome.

Pfizer and Moderna have provided the vast majority of COVID-19 vaccines in the US. More than 200 million Americans have been fully vaccinated with these companies’ two-dose vaccines, while less than 17 million Americans have been vaccinated by J&J.