The delta variant, first identified in India in December 2020, has become the most dominant strain of COVID-19 in the U.S., according to CDC data.
“We know that the delta variant has increased transmissibility and it is currently surging in pockets of the country with low vaccination rates,” CDC Director Dr. Rochelle Walensky said during a White House COVID-19 Response Team briefing on Thursday. The video above has highlights from said briefing.
Weeks ago, just over a quarter of new U.S. cases stemmed from the delta variant. Nationwide, it now accounts for more than half of COVID-19 cases. In some places, like parts of the Midwest and upper mountain states with lower vaccination rates, roughly 80% of cases stem from the delta variant.
“We also know that our authorized vaccines prevent severe disease, hospitalization and death from the delta variant,” Dr. Walensky added. “These results have been observed not just here in the United States, but in other countries, as well.”
Researchers from France’s Pasteur Institute reported new evidence Thursday suggesting a second dose of Pfizer or AstraZeneca vaccines boosts immunity to the point of neutralizing the delta variant.
British researchers found two doses of the Pfizer vaccine are 88% effective against symptomatic infection and 96% effective against hospitalization with the delta variant.
“Let me emphasize that if you are vaccinated, you have a very high degree of protection and therefore you do not need to wear a mask,” National Institutes of Allergy and Infectious Diseases Director Dr. Anthony Fauci said.