5 experts who will vote on the fate of J&J's vaccine believe we should end the pause - and possibly add a warning for women

• On Friday, a federal advisory committee will vote on what to do with Johnson & Johnson's COVID-19 vaccine.
• The vaccine is on pause across the US after six reports of rare blood clots in young to middle-aged women who'd recently been vaccinated.
• Insider spoke with 5 of the 15 committee members. They said they're eager to end this pause.

America's top public health experts are itching for one thing: more information.

Ever since six cases of rare, but potentially life-threatening blood clots showed up in women who had recently been vaccinated with Johnson & Johnson's one dose COVID-19 vaccine, doctors and public health pros have been trying to determine whether this very, very rare event could be related to the shot.

These highly unusual brain clots, though exceedingly rare, have shown up in about one in a million vaccine recipients so far, resulting in one death. More cases may still be unreported (the clots we know about haven't shown up until 6-13 days after vaccination), making it hard for experts to gauge the true scale of the issue.

Last week, an independent advisory committee that makes vaccine recommendations to the Centers for Disease Control and Prevention made a plea to shot-givers across the US: let's continue to pause use of this vaccine for now, to gather more data on how many of these dangerous clots are really out there.

But all signs are suggesting that the pause could be coming to an end this weekend.

Insider spoke with five of the 15 CDC vaccine advisory committee members who are meeting on Friday to vote on whether to continue the J&J pause across the US. Barring any more major surprises in the data, they all seemed eager to get the vaccine back into syringes and arms across the nation ASAP.

Millions of Americans got the shot before it was paused

To date, more than 8 million people across the US have been vaccinated with J&J.

As of last Wednesday, monitoring from the federal government and J&J collectively had flagged a total of seven worrisome clot cases in women under the age of 60, plus one case (during clinical trials) in a young man.

CDC Director Rochelle Walensky hinted at a White House briefing earlier this week that at least another "handful" of cases have been spotted during this week and a half long pause.

Are these one-in-a-million clots caused by the vaccine, or just a fluke?

The clots, cases of cerebral venous sinus thrombosis (CVST) are especially worrisome because they come with low blood platelet levels (thrombocytopenia). That means one of the most common blood clot treatments (heparin) only makes them worse.

Symptoms almost always start with a headache and some chills. Then they progress into severe abdominal pain and loss of consciousness. Eventually they can lead to brain damage and language impairment.

Some on the advisory committee, like Dr. Kevin Ault, an OBGYN at the University of Kansas, still haven't ruled out the possibility that these cases could just be a fluke, and not related to vaccine administration at all. Others are more convinced this rare but worrisome issue is a highly unusual vaccine reaction.

"I think almost surely this is going to turn out to be related to the vaccine because of the clustering and because of the extraordinary, unusual presentation and findings of the patients who have it," Dr. Sarah Long, a professor of pediatrics at Drexel University who's serving on the committee, said.

Without more data, advisors say they are sort of flying blind

Every expert on the committee that Insider spoke to said they want to know if there have been any more cases of the rare blood clots reported in the interim.

That will help them better decide whether to warn certain populations (like young women) about getting this shot.

"We're a data-driven group. So I want to see data," Ault said. "We're glad the system worked, that we were able to find a one in a million potential problem, with this rather unusual diagnosis."

Advisors may ask for the shot to come with a warning for women

Long said if cases continue to be clustered in younger women, there could be a warning given out with the shot,
"or we could say we recommend it only for men and older women."

Dr Wilbur Chen, a professor at the University of Maryland School of Medicine on the committee, is hopeful that with more public awareness about the rare condition, it can be recognized early and treated appropriately, avoiding prolonged hospitalizations and more deaths.

"For women 18 to 48 years, or 18 to 50 maybe, we may say 'you may get vaccinated, but we'd like to just make sure that you are aware of this very rare event,'" he said.

Like putting on a helmet before riding a bike or fastening a seatbelt before driving a car, safety measures can be implemented, he added.

"You can't completely remove risk with any vaccination, but you can darn well try to make sure that you reduce risk as much as possible," Chen said. "And that's what we're trying to do at this point."

Ultimately, all of the advisors want us to find a way to reap the benefits of this one-shot vaccine

Experts desperately want to put the J&J shot to use. It is the only one-shot COVID-19 vaccine on the market in the US, making it a critical tool in places like college campuses, homeless shelters, and for homebound adults who may all have logistical challenges to getting a second shot.

"I think it's extremely unlikely that we're going to say it's too risky to use this vaccine," Dr. Jose Romero, chair of the advisory committee, and director of the Arkansas Department of Public Health, said, suggesting that the issue is likely an "abnormal immune response" that a very small number of patients may have to the shot.

Romero, like others on the committee, is hopeful that the pause will reinforce public confidence in the vaccine safety system. But, with new variants spreading quickly, they all know time is of the essence.

"I'm not willing and eager to continue the pause for much further," Chen said. "The truth is that the value of the vaccine is proven. 100% efficacy against hospitalization and death is virtually what the data is showing, so that's terrific. And on the other side for the safety, we think that this [clotting] is super rare."

'Are we blowing this up out of proportion?'

Other committee members have warned that the longer this pause goes on, the more hesitant people may be to take the shot once it's back in action.

"I have mixed feelings," Lynn Bahta, an infectious disease nurse at the Minnesota Department of Public Health who is also on the panel, said. "Are we blowing this up out of proportion?"

She agreed it's important that the public knows experts are being cautious and careful, taking vaccine safety seriously, but "to keep delaying is not helpful," she said.

Some states, like Maine, were planning to rely heavily on J&J to vaccinate homebound residents, and they are now having trouble getting as many people vaccinated as quickly as they had originally intended.

Dr. Walensky has signaled that as soon as the advisory committee makes a final decision on Friday, the CDC and FDA will work together to quickly incorporate their advice into the national vaccination plan.

"I don't want to get ahead of the advisory committee," she told NBC's Today show Thursday, while adding "I'm really hopeful that we'll be able to use the [J&J] vaccine soon."