The U.S. health agencies’ decision to recommend a pause in administering the Johnson & Johnson vaccine nationwide stirred up confusion on Tuesday, leaving many with questions.
The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) issued a joint statement early Tuesday calling to temporarily halt the use of the Johnson & Johnson vaccine so the agencies could review rare cases of blood clots among recipients.
The agencies said there were six reported cases of blood clots, with one being fatal, out of the more than 6.8 million Johnson & Johnson doses administered.
FDA, CDC and White House officials addressed concerns about the vaccine and the interruption to rollout in a series of statements and briefings, although some questions remain unanswered.
Here are five questions raised by the pause in the Johnson & Johnson vaccines.
Who made the decision to pause and why?
The FDA and CDC initially announced that the agencies advised the U.S. to temporarily stop administering Johnson & Johnson vaccines after finding six cases of a blood clot called cerebral venous sinus thrombosis (CVST) among vaccine recipients.
During an afternoon White House press briefing, top infectious diseases expert Anthony Fauci attributed the “thoroughly made” decision to the two agencies, saying the conclusion was “ruled by the science and not by any other consideration.”
Jeff Zients, the White House coordinator for the COVID-19 response, said the White House was informed on Monday night that the agencies would make an announcement on Tuesday morning and “had no other involvement.”
In a separate morning press conference, FDA and CDC officials affirmed that the agencies made the recommendations to ensure safety and transparency and allow time for a review of the blood clot cases.
Health officials said physicians usually treat blood clots with heparin, but with CVST, using heparin could be dangerous, and other treatments are needed.
“When we saw this pattern and were aware that treatment needed to be individualized for this condition, it was of the utmost importance for us to get the word out,” said Anne Schuchat, the principal deputy director at the CDC.
Who is impacted?
The six cases of CVST under investigation by the agencies occurred among women aged 18 to 48 who received the Johnson & Johnson vaccine six to 13 days prior to developing symptoms. One of these women died, and another is in critical condition.
When asked if the vaccine should be restricted among women to those older than 50, Fauci said, “It is entirely conceivable, making no predictions, that there may be some restriction in an age group or not.”
“We don’t know that,” he added. “That’s the reason they’re working very hard to answer the question you’re asking.”
For those who got the Johnson & Johnson vaccine more than a month ago, Schuchat said the risk of developing symptoms is “very low.”
People who got the vaccine in the last three weeks were instructed to keep an eye out for symptoms such as severe headaches, abdominal pain, leg pain and shortness of breath. If those symptoms arise, the recipients should contact their health care providers and seek treatment, Schuchat said.
Fauci told people who got the Johnson & Johnson vaccine that they shouldn’t “get an anxiety reaction,” as there’s a “less than one in a million” chance of developing the symptoms.
How long will the pause last?
The timeline for the halt in Johnson & Johnson vaccinations remains up in the air, health officials have repeatedly said.
Acting FDA Commissioner Janet Woodcock said the time frame for the pause “will depend obviously on what we learn in the next few days,” noting officials expect it “to be a matter of days.”
Schuchat said the agencies are “committed to an expeditious review” and to reaching out to physicians to ensure they know how to diagnose and treat any CVST blood clots.
“Our intent is in the days ahead to provide an update regularly and that the pause provides us time for deliberation and assuring appropriate diagnosis entry,” she said.
When asked about a timeline for the agencies’ review, Fauci said, “I don’t know what they’re gonna be doing.”
He added, “What I heard from the previous press discussion is it’s going to be more like days to weeks rather than weeks to months.”
Will the pause impact the U.S.’s vaccine supply and ability to reach the goal of 200 million doses in President Biden’s first 100 days?
The White House released a statement saying it does not expect the pause to have a “significant impact” on the vaccination supply and administration effort due to available doses of the Pfizer-BioNTech and Moderna vaccines.
In his statements, Zients said the U.S. has “plenty of supply,” noting that more than 25 million doses of the other two vaccines go out each week. He said that Johnson & Johnson vaccines made up less than 5 percent of the total doses administered in the U.S. so far since Johnson & Johnson’s vaccine was authorized months after the other two.
“We have more than enough supply of Pfizer and Moderna vaccines to continue the current pace of about 3 million shots per day,” he said.
The health experts said they did not expect the halt in Johnson & Johnson vaccinations to affect President Biden’s goal to administer 200 million doses by his 100th day in office, as Fauci said there are no “red flag signals” about the Pfizer-BioNTech and Moderna vaccines.
Schuchat said the government’s partners are working on rescheduling appointments for those scheduled for Johnson & Johnson vaccines in the coming days.
“This may be a bit bumpy,” she said. “We want to make sure that we’re getting the word out to the public and to our providers, but we do want to make sure that people who are scheduled to have vaccinations will be able to get that.”
How could the pause affect vaccine hesitancy across the country?
Officials also addressed the potential effect the temporary halt of the Johnson & Johnson shots could have on the existing vaccine hesitancy across the country, particularly among Republicans.
“Look, hesitancy amongst a group of people is a challenge, and we need to be addressing it, and we are,” Zients responded when asked if the move would increase or decrease hesitancy about the vaccine.
Zients and Fauci said the decision to pause the Johnson & Johnson vaccine distribution communicates to Americans that federal agencies are ensuring the safety of the vaccines.
“The fact that a pause was done, I think, is just a testimony to how seriously we take safety and why we have an FDA and a CDC that looks at this very carefully, and hopefully will resolve it within days to weeks,” Fauci said. “I think it’s a very strong argument for safety, actually.”
Woodcock said her message to those who haven’t been vaccinated is to keep getting vaccines that are available “because the risks from the pandemic are significant.”
“The government is really looking into, very carefully, any safety problems so that they can be managed properly with this particular vaccine and all vaccines,” she said.
–Updated on April 14 at 6:00 a.m.