The Delta coronavirus variant is expected to become the dominant strain in the Untied States, said the U.S. Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky on Friday.
The Delta variant, also known as B.1.617.2, is more transmissible than others, she said.
"As worrisome as this Delta strain is with regard to its hyper transmissibility, our vaccines work," Walensky said.
"Right now, they are working and they require actually two doses to be fully vaccinated, to work well. So I would encourage all Americans, get your first shot and when you're due for your second, get your second shot and you'll be protected against this Delta variant," she said in an interview with ABC News.
The CDC has elevated the Delta variant from "variant of interest" to "variant of concern".