What to Know About the Johnson & Johnson COVID-19 Vaccine Pause

Fast facts:

• Use of the Johnson & Johnson’s COVID-19 vaccine has been paused so the CDC and FDA can investigate a rare but severe side effect.
• So far this side effect has appeared in six reported cases, all arising six to 13 days after vaccination.
• The White House is urging the public not to be concerned. 
• The Johnson & Johnson vaccine works slightly differently from Pfizer and Moderna, but still appears to be an effective way to prevent severe infection from coronavirus.
• For more information about the COVID-19 vaccine, you can visit the CDC’s website.
• CBS News is offering live updates about the Johnson & Johnson vaccine pause here. 

Use of Johnson & Johnson’s COVID-19 vaccine is being paused in the U.S. so the Centers for Disease Control (CDC) and Food and Drug Administration (FDA) can investigate what they call a rare and severe side effect. Since the Johnson & Johnson vaccine was approved for emergency use in late February, about 6.8 million doses have been administered, according to a joint statement from the two organizations, addressing the pause.

Today FDA and @CDCgov issued a statement regarding the Johnson & Johnson #COVID19 vaccine. We are recommending a pause in the use of this vaccine out of an abundance of caution.

— U.S. FDA (@US_FDA) April 13, 2021

All COVID-19 vaccines have the potential to produce some common side effects like a sore arm, body aches, fatigue or flu-like symptoms. But six cases of a rare and severe type of blood clot have surfaced among women between the ages of 18 and 48. The type of blood clot is called cerebral venous sinus thrombosis (CVST) and it can occur when there are low blood platelet levels present.

In all six cases symptoms arose between six and 13 days after vaccination. Typically, treatment for a blood clot calls for administration of the anticoagulant drug heparin, but in the case of CVST heparin can create complications so doctors must use alternative treatment methods. The CDC was not specific about what that entails.

The CDC and FDA will now convene an advisory committee and review board to evaluate these cases and weigh their potential significance on overall vaccination efforts. They also stress that the pause is to give health care providers time to plan to recognize and treat these blood clots, should they occur.

Speaking on a media call, Dr. Peter Marks, Director, FDA Center for Biologics Evaluation and Research, said experts don’t have a definitive cause yet for these cases of CVST. “We can speculate a similar mechanism that may be going on with other adenoviral vector vaccine [Oxford-AstraZeneca]. That is, this is an immune response, that occurs very, very rarely after some people receive the vaccine, and that immune response leads to activation of the platelets and these extremely rare blood clots.”

Anyone who has received the Johnson & Johnson vaccine and develops a severe headache, abdominal pain, leg pain or shortness of breath within three weeks should contact their doctor, the statement advised.

Jeff Zients, the White House COVID-19 response coordinator released a statement urging the public not to be concerned about this temporary pause’s impact on vaccination efforts. The Johnson & Johnson vaccine comprises less than five percent of current vaccine use, he said. And the U.S. has already ordered enough Pfizer and Moderna doses to vaccinate 300 million Americans. He said they are working with state and federal partners to get anyone currently scheduled for a Johnson & Johnson vaccine rescheduled for a Pfizer or Moderna option.

Johnson & Johnson said they are reviewing the cases of blood clots with European health officials and have temporarily decided to delay the release of their vaccine in Europe.

The Johnson & Johnson vaccine works slightly differently from the highly touted mRNA technology of Pfizer and Moderna, but the effect is the same — it prevents severe infection from coronavirus. It works through a process known as viral vector, in which a modified version of a different virus — not the coronavirus — is delivered into cells. This virus has instructions on it that tell the body to produce a harmless piece of the virus that causes COVID-19. Our body recognizes this piece as a foreign invader and begins to build defenses against it in the form of immunity. The Johnson & Johnson vaccine had an efficacy rate of 66 percent in clinical trials. 

Marks said this pause is not a mandate but a recommendation, according to NPR. “We are not going to stop a provider from administering the vaccine,” he said, but doctors and patients should work together to determine the best course of action for them.