Transcript for CDC says it needs time to respond to Johnson & Johnson concerns
Good evening. It's great to have you with us on a Wednesday night. We begin with the breaking headline from the CDC, an advisory committee late today leaving the temporary pause for the Johnson & Johnson vaccine in effect. Saying they need to know more after rare reports of six women who suffered severe blood clots. One died, another in the hospital. This affecting about 1 in 4 vaccine sites in the country giving the Johnson & Johnson vaccine. The panel adjourning without a clear recommendation, saying they'll try to meet again in a week to ten days. The Johnson & Johnson vaccine using similar technology to the astrazeneca vaccine in Europe. At least 19 reported deaths from blood clots there. And the white house saying there's more than enough vaccines to vaccinate all Americans still. Steve osunsami leading us off tonight with late news from the CDC in Atlanta. Reporter: A CDC advisory panel tonight says it needs more time and information to respond to the new concerns about the Johnson & Johnson vaccine. Which means for now, Americans should continue holding off using this brand of the covid vaccine. We do not have to arrive at a vote today or a recommendation today. If we need more time to think about this, we can reconvene later this week or this weekend Reporter: A very small number of women who suffered blood clots after getting the shot caused health officials to put a hold on using the drug. Health officials here worry that this potential adverse reaction looks a little too similar to what happened in Europe with the astrazeneca vaccine. The astrazeneca vaccine is made using similar technology as the Johnson & Johnson, and in Europe 19 people died. There are some rather strong similarities about this with regard to the time frame following vaccination. Particularly importantly, the clinical syndrome of these clots together with low platelets. So there are a lot of similarities there that you just can't miss that. Reporter: The scientists are looking for any link between the six women who got sick, and they're investigating whether the blood clots were an immune response. All six women were between 18 and 48 years old. They got sick within two weeks of getting vaccinated. Some of the clots formed in veins of the sinus and prevented blood from draining out of the brain. One woman died. Three are still hospitalized. The holdup on using the Johnson & Johnson vaccine has had a huge impact on these 7,000 locations where it was the only shot they were giving. 1 out of every 4 vaccine locations in America was only using Johnson & Johnson. I get why they're doing it, out of the abundance of caution. But the statistics were so low to get the blood clotting, I was willing to take the risk anyway. Reporter: The race is on to find available shots from pfizer and modern for appointments that are already scheduled. This is all the pfizer and modern I have. Of course it makes it very hard because I have hundreds of doses of Johnson that I can't use. Reporter: They're pretty frustrated at this clinic in los Angeles that's already been struggling to vaccinate underserved communities. Tonight, the Biden administration is saying that there's still more than enough vaccine. I want to be clear that we have more than enough pfizer and modern vaccine supply to continue or even accelerate the current pace of vaccinations. All right. Steve osunsami live at the CDC tonight. I know the advisory committee plans to meet again on this. Any idea how soon? Reporter: David, this group's next meeting is scheduled for may 5th. But they're hoping to meet again in a week or so. There was a lot of concern about making a decision without all the proper information. They're also still watching about 3 million Americans who have recently gotten the Johnson & Johnson vaccine within the last few weeks. They say it's possible we could see a few more of these rare cases that concern them. Steve, thank you.
This transcript has been automatically generated and may not be 100% accurate.