The spread of the Delta variant of the coronavirus will pose a serious risk this summer to people who are not fully vaccinated, according to Dr. Ashish Jha, dean of Brown University's School of Public Health.
"If you have not gotten vaccinated, this is a potentially very dangerous time because the Delta variant is spreading," Jha said Tuesday in the latest edition of the "COVID: What Comes Next" podcast hosted by The Providence Journal.
"It's about 6% of infections in the United States right now, doubling every two weeks. If you do the math, in about four to six weeks we'll start getting close to half. … By mid-August, it'll be the dominant variant in the United States."
The Delta variant is highly contagious and more deadly, and may be more resistant to vaccines, he said.
"It is the most contagious variant we have ever seen in this pandemic and that's going to be a huge problem," Jha said. "Second, it does look like it's a bit more deadly than other variants. And there is some evidence that it has more 'immune escape' as well. So, it may be one of the first sort of true triple threats."
A vaccination is still the best defense, he said.
He also welcomed recently reported results of clinical trials of the Novavax vaccine showing a 90.4% overall effectiveness. He envisions the new vaccine playing a critical role elsewhere on the planet, given adequate supplies of the Moderna, Pfizer and Johnson & Johnson vaccines in the U.S.