CDC labels highly transmissible delta strain a COVID-19 ‘variant of concern’

The Centers for Disease Control and Prevention (CDC) is labeling the highly transmissible delta strain of the coronavirus a “variant of concern” amid growing concerns about the strain fueling outbreaks among unvaccinated people in the United States.

“Today the CDC announces the Delta variant as a variant of concern,” tweeted White House spokesman Kevin Munoz. “The stakes are high for those who are unvaccinated but the vaccines work.”

The delta variant, first identified in India, is believed to be about 60 percent more transmissible than a previous variant known as alpha, according to British researcher Neil Ferguson. The delta variant has become dominant in the United Kingdom.

Health experts also say the delta variant could cause more severe disease and an increased risk of hospitalization.

“This change is based on mounting evidence that the Delta variant spreads more easily and causes more severe cases when compared to other variants, including B.1.1.7 (Alpha),” a CDC spokesperson said. “Two doses of the mRNA vaccine are effective against this variant and other variants currently circulating in the United States.”

The Pfizer and Moderna vaccines, both mRNA vaccines, are about 88 percent effective against the delta variant after two shots.

Former Food and Drug Administration Commissioner Scott Gottlieb said in an interview with CBS News on Sunday that the Johnson & Johnson vaccine “also appear[s] to be effective” against the delta variant, though perhaps at a level closer to 60 percent.

Much of the vaccine research has focused on the Pfizer and Moderna vaccines, which make up the large bulk of vaccinations in the U.S.

The CDC’s move was first reported by Fox News.

Experts say the rise of the delta variant further underscores the importance of vaccinating more Americans, to stem any potential COVID-19 spikes in the U.S.

It is also important that people get both shots of the Pfizer and Moderna vaccines, experts say, since one shot is much less effective against the delta variant.

The concern is that the more transmissible delta variant could fuel spikes in areas of the U.S. with lower vaccination rates.

Anthony Fauci, the nation’s top infectious disease expert, said the delta variant comprised about 6 percent of U.S. cases last week.

Gottlieb on Sunday said the delta variant is doubling in prevalence in the U.S. every two weeks.

“I think in parts of the country where you have less vaccination, particularly in parts of the South, where you have some cities where vaccination rates are low, there’s a risk that you could see outbreaks with this new variant,” Gottlieb told CBS News.

Updated at 1:50 p.m.