Transcript for UK variant has become most dominant COVID strain in US, CDC says
The top fight against the pandemic. 110 million Americans have received at least one dose of the vaccine. That is over 42% of the adult But there are new concerns this morning about the contagious uk variant which the CDC says is now the dominant source of infections and its victims are younger than before. According to the CDC, five states are now accountng for almost half the new cases in the U.S. One of those states is Florida and erielle reshef joins us from Miami, from a Miami vaccination site with the very latest. Good morning, erielle. Reporter: Good morning to you, Michael. Florida has the most confirmed cases of that concerning uk variant surpassing 3,000. We're here at this mass vaccination site, one of the busiest in the state. If you look at our drone cam the lines have been forming. People here as early as 3:00 A.M. Eager to get that shot. Experts say it is a race against time to stop these variants and stop the spread. This morning, the CDC saying as predicted months ago, the highly contagious variant of covid, b.1.1.7 also known as the uk variant is now the most dominant strain of the virus spreading here in the U.S. The CDC saying while vaccines are effective in fighting it, the variant which is believed to be more deadly could be fueling what some experts fear could be the start of a new surge. Experts saying lifted covid-19 restrictions and increased travel also to blame. The virus still has hold on us, infecting people and putting them in harm's way and we need to remain vigilant. Reporter: Like all the prior variants, experts b.1.1.7 can also infect children and unvaccinated adults. It's been estimated to be between 50% and 100% more infectious than the previous strains of virus. Reporter: According to authorities at one Wisconsin day care at least 16 children age 6 and under tested positive for the uk variant this week. Along with five day care workers and 14 of their family members. I think we were all stunned by the news. Reporter: The CDC saying five states are now accounting for almost half of the new cases in the U.S. I'm going to take you inside and show you how we care for our patients. Reporter: One of those is Florida. Icu nurse Jesse bozill giving us a look. All of our patients are here on the ventilators. Reporter: Now more than a year after it was first declared a global pandemic, frontline workers still pushed to the brink fighting the deadly virus. We're beyond tired. We are exhausted. Reporter: 38 states have now opened vaccine eligibility to people 16 and older and despite the rise in cases the CDC says deaths are down 20% likely due to the vaccine.
This transcript has been automatically generated and may not be 100% accurate.