• Dr. Wilbur Chen expects the J&J Covid vaccine pause will eventually be lifted.
• "I think there's a huge amount of evidence that the benefit greatly outweighs this risk," the University of Maryland School of Medicine professor told CNBC on Friday.
• Chen is a member of a CDC advisory panel meeting Friday to discuss the vaccine halt.

A member of a key CDC advisory panel told CNBC on Friday morning that he expects the U.S. pause on Johnson & Johnson's one-dose coronavirus vaccine to eventually be lifted.

"I think that there is a willingness for us to use this vaccine. We did need to make an important pause to be able to look at this safety information to be able to consider the risks. But certainly, I think there's a huge amount of evidence that the benefit greatly outweighs this risk," said Dr. Wilbur Chen, a professor at the University of Maryland School of Medicine.

Chen spoke on "Worldwide Exchange" hours before taking part in a meeting later Friday of the agency's Advisory Committee on Immunization Practices to discuss the rare, but severe, blood clotting disorder that a few women experienced after receiving the J&J shot.

In addition to the six who developed rare but severe blood clotting issues after getting the vaccine, the CDC is looking into two more possible cases: an Oregon woman who died and a Texas woman who was hospitalized. Of the original six women, one died and one became critically ill. There's been roughly 8 million J&J vaccine doses administered.

Concerns over the issue led the Centers for Disease Control and Prevention and the FDA to last week temporarily halt the use of the J&J vaccine in the U.S. However, when asked by CNBC's Brian Sullivan whether he believes Americans will start receiving the J&J vaccine at some point, Chen said, "Yes."

The Advisory Committee on Immunization Practices, known as ACIP, is an outside panel of experts that makes recommendations to the CDC. It convened a meeting last week on the J&J vaccine, but postponed a decision until this week. Ultimately, it's up to the CDC and Food and Drug Administration on what to do next.

Chen said ACIP now has better information on the blood clotting issues upon which to base its vaccine guidance. "We will be able to get a good case count. It may not be perfect, but we don't need to have perfect to have actionable information," Chen said, adding he expects the panel to "come up with a set of recommendations that I think everybody will be happy with."

In an emailed statement to CNBC, CDC Director Dr. Rochelle Walensky said she hopes the public health agency receives a "recommendation that takes into account the risk versus reward of using the Johnson & Johnson vaccine based on the new case data and the risk-benefit analysis CDC has been conducting over the last week."

"I truly appreciate the complex question before the committee and look forward to hearing from them. I also appreciate the importance of acting swiftly, in collaboration with the FDA, once we hear from ACIP," Walensky added.

Given the urgency of the coronavirus pandemic, some people have criticized the decision to halt the J&J Covid vaccine — which only requires one dose for full immunity protection — while the investigation into blood clots took place.

Chen disagreed.

"The risk is very, very minor but until we were able to fully consider that information, we could not contextualize that to the rest of the medical community and also to the public as well," he said. "We've only paused for 10 days. Hopefully that will not be harmful in the long run, but we of course want to engender that there is some confidence in the system for collecting safety information."

The other two Covid vaccines approved for emergency use in the U.S. are from Pfizer and Moderna; both of them require two shots.