Johnson & Johnson vaccine: Four-hour CDC meeting fails to deliver definitive decision on pause

The FDA is investigating six confirmed cases where women developed severe blood clots

An independent advisory committee to the Centers for Disease Control and Prevention (CDC) met on Wednesday to discuss the recommended pause in administering the Johnson & Johnson vaccine after six people developed severe blood clots.

After a four-hour discussion, the Advisory Committee on Immunization Practices (ACIP) agreed that more time was necessary to review data and potential health risks prior to voting on a recommendation. Members of the committee instead opted to not vote on their recommendations on whether the vaccine should be continued or discontinued.

A vote would not happen for at least another seven to 10 days until the panel reconvened again. As a result, the pause would likely continue until the panel could reach a recommendation for the CDC.

The CDC convened an emergency meeting of its ACIP after it announced alongside the Food and Drug Administration (FDA) on Tuesday that the federal agencies were recommending for states to pause administering the Johnson & Johnson vaccine.

More than 7 million single-dose vaccines have been administered to Americans, but the FDA is now investigating six confirmed cases where women ages 18 to 48 developed severe blood clots following inoculation. Symptoms such as severe headache and abdominal pain started for the women six to 13 days after receiving the vaccine.

One woman died after she developed a blood clot and another was in critical condition, health officials said.

The announcement from the federal health agencies encouraged all 50 states, Washington DC, and Puerto Rico to halt using the Johnson & Johnson vaccine until a new recommendation was reached between experts.

In the last two weeks, the United States has administered about 3.8 million doses of the Johnson & Johnson vaccine. Members of the committee wanted to take the time to see if more blood clot cases developed prior to making their determination, and some warned more instances would likely occur in the coming weeks.

During the meeting, the experts reviewed and debated current information and data available about the rare blood clots, while also learning of a potential seventh case. Members of the public were then allowed to speak before the committee discussed if it should vote.

The rare disorder, called cerebral venous sinus thrombosis (CVST), causes blood clots to form in the brain that are different from the typical blood clots healthcare providers are used to treating.

One purpose of the recommended pause by the FDA and CDC was to give healthcare providers enough information so they could better assess and treat their patients if more cases were to arise.

Not only was the ACIP panel reviewing the six confirmed cases, but they were also discussing whether the risk of the shot outweighs the potential benefits.

“We do need to better understand the risk, which we know is going to be very rare, very low, but we really don’t know exactly how low and how to correctly characterise it,” said Dr Beth Bell, a clinical professor at the University of Washington in Seattle, during the ACIP’s meeting. “I think we need to not vote and gather the necessary information so we can make an evidence-based decision.”

Panel members also stressed that they didn’t necessarily believe the vaccine was dangerous, but that they wanted to show caution until more information was gathered – specifically since millions of Americans were in that two-week window of having received the jab. 

Several members indicated that the availability of the Pfizer and Moderna vaccine, both which have no reported cases related to severe blood clots, were adequate vaccine options for Americans in the meantime.