The Advisory Committee on Immunization Practices (ACIP), a panel of outside experts that advises CDC on vaccines, on Wednesday declined to vote on whether use of Johnson & Johnson's (J&J) single-dose vaccine should resume—leaving the federal government's recommended pause in place until the committee's next meeting, which is expected within 10 days.

ACIP declines to vote on whether to resume use of J&J's vaccine

CDC and FDA in a statement Thursday recommended a pause in the use of J&J's single-dose Covid-19 vaccine after six people—out of about 6.8 million Americans who have received the vaccine so far—developed a rare and severe type of blood clot called cerebral venous sinus thrombosis (CVST) six to 13 days after vaccination. According to the statement, the agencies recommended the pause "out of an abundance of caution" as CDC and FDA scientists examine the potential link between the vaccine and CVST.

On Wednesday, ACIP members met to vote on whether to restart the use of J&J's vaccine, Politico reports. During the meeting, ACIP members reviewed new information on the six cases of CVST—which occurred among women between the ages of 18 and 48—shared by an CDC official and a J&J executive.

The CDC official and J&J executive provided new details on the women who developed CVST, noting they were all white and only one of them was taking hormonal contraceptives that can cause blood clots—suggesting contraception did not play a role in the CVST cases.

Tom Shimabukuro, a member of CDC's Covid-19 task force, said the CVST cases among J&J's vaccine recipients are alarming because they were coupled with low levels of blood cells involved in clotting, which is a combination rarely seen among healthy young people.

"We have a picture where we have clots forming in large [blood] vessels in the presence of low platelets, so it's kind of a paradox here," Shimabukuro said. "This is unusual—it usually doesn't happen."'

Separately, Aran Maree, CMO for Janssen, the division of J&J that developed the vaccine, presented data on two cases of blood clots among people who received the company's vaccine during a clinical trial, including one trial 25-year-old participant whose symptoms closely matched those of CVST.

Maree during her presentation said, "I'd like to reiterate that, based on the current data, Johnson & Johnson believes the overall benefit-risk profile for a vaccine is positive across the population for which it is authorized."

Although the committee had been scheduled to vote on whether to proceed with the recommended pause, several ACIP members said they believed they didn't have sufficient data to estimate the risks and benefits of J&J's vaccine or recommend limits on the vaccine's use.

For example, Beth Bell, a clinical professor at the University of Washington, said, "I just don't feel there's enough information to make an evidence-based decision. We won't have all the information, but I think there are some things that we can gather relatively quickly, which all have to do with the benefit/risk balance. 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 characterize it."

Committee members discussed a number of potential actions the federal government could take, including lifting the pause for certain subsets of the population and extending the pause for at least a month, STAT News reports.

Doran Fink, an FDA official, also proposed resuming the vaccine's use as researchers continue to investigate the vaccine's potential risk. In the meantime, Fink said providers and patients could be given information about the potential risks to allow patients to determine whether they want to received J&J's vaccine. "Our current thinking is that this risk could be managed by inclusion of warning statements," Fink said.

Some committee members noted that the committee's delay in acting could have serious consequences on vaccination efforts in the United States and abroad.

For instance, some committee members warned that an extended pause could damage public confidence in the vaccine and hurt vaccination efforts among underserved populations. According to experts, it's easier to vaccinate these populations with J&J's single-dose vaccine, which can be more easily stored and shipped than the Covid-19 vaccines developed by Moderna and Pfizer/BioNTech.

"We are in a situation where not making a decision is tantamount to making a decision," Nirav Shah, director of the Maine Center for Disease Control and Prevention and a non-voting representative to the ACIP, said. "Any decision to pause will invariably result in the fact that the most vulnerable individuals in the United States, who were prime candidates for the [J&J] vaccine, will remain vulnerable. The most at risk will remain at risk."

The members of the committee acknowledged the urgency of making a decision on whether to resume the use of J&J's vaccine and agreed to reconvene within 10 days to vote on a recommendation.

Although the committee's recommendations are non-binding, federal health officials have said they intend to use its advice and a separate investigation by FDA to guide their decision-making, Politico reports.

What an extended pause could mean for America's vaccination campaign

Even as some experts argued an extended pause could fuel vaccine hesitancy, some federal officials said the move could instead build people's trust in vaccine safety.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and chief medical advisor for the White House's Covid-19 response, said he believes the pause confirmed "how seriously we take safety even though it's a rare event." Fauci continued, "If anybody's got a doubt that 'Oh, they may not be taking safety very seriously,' I think this is an affirmation that safety is a primary consideration when it comes to … [FDA] and … [CDC]. That's why it was done."

In addition, federal officials have said they don't expect the pause to significantly hamper America's vaccination campaign.

Jeff Zients, the White House's coronavirus response coordinator, said the United States may see a drop in the daily number of administered vaccine doses in the short term. "However, I want to be clear that we have more than enough Pfizer and Moderna vaccine supply to continue working to accelerate the current pace of vaccination," Zients said.

Where the US coronavirus epidemic stands

The J&J vaccine pause comes as the United States is racing to vaccinate Americans to prevent coronavirus cases. According to Axios' "Vitals," many parts of the United States are relying heavily on vaccines to contain the virus, shifting away from mandated social distancing measures aimed at curbing the coronavirus's spread.

According to data compiled by the Times, the United States' average daily number of newly reported coronavirus cases over the past week was 71,511—up by 11% compared with the average from two weeks ago.

The Times' data showed that, as of Thursday morning, the rates of newly reported coronavirus cases were "staying high" in Washington, D.C , Puerto Rico, and 27 states that have reported a daily average of at least 15 newly reported cases per 100,000 people over the past week. Those states are Alaska, Colorado, Connecticut, Delaware, Florida, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nebraska, New Hampshire, New York, North Carolina, North Dakota, Ohio, Pennsylvania, Rhode Island, South Dakota, Tennessee, Virginia, Washington, West Virginia, and Wisconsin.

In addition, the rate of newly reported coronavirus cases was "going up" as of Thursday morning in three states—Montana, Nevada, and Oregon—that had been seeing comparatively lower case rates. In the remaining states and U.S. territories, rates are "going down" or "staying low," according to the Times' analysis.

Similarly, hospitalizations Covid-19 hospitalizations are rising again. According to data from the Times, 45,308 Americans with Covid-19 were hospitalized for treatment as of Thursday morning—up by 8% compared with the average from two weeks ago.

Even as coronavirus cases and hospitalizations climb throughout the country, the number of newly reported deaths linked to the coronavirus has continued to decline. According to data compiled by the Times, 932 new deaths were linked to the coronavirus on Wednesday, down 19% compared with the average from two weeks ago.

(Owermohle/Banco, Politico, 4/14; Branswell, STAT News, 4/13; Grady/Zimmer, New York Times, 4/14; Sun/Johnson, Washington Post, 4/14; Maxouris, CNN, 4/15; Lovelace, CNBC, 4/14; Owens, "Vitals," Axios, 4/15; New York Times, 4/15).