▶ Watch Video: Gottlieb says coronavirus Delta variant likely to become dominant U.S. strain Washington — Dr. Scott Gottlieb, the former commissioner of the Food and Drug Administration, said Sunday that a coronavirus strain known as the Delta variant is likely to become the dominant source of new infections in the U.S. and could lead to new outbreaks in the fall, with unvaccinated Americans being most at risk. “Right now, in the United States, it’s about 10% of infections. It’s doubling every two weeks,” Gottlieb said on “Face the Nation.” “That doesn’t mean that we’re going to see a sharp uptick in infections, but it does mean that this is going to take over. And I think the risk is really to the fall that this could spike a new epidemic heading into the fall.” The Delta variant, also known as B.1.617.2, was first discovered in India and is one of three related strains. It has become infamous for its ability to outpace and replicate quicker than other variants in its lineage. Transcript: Scott Gottlieb on “Face the Nation” Gottlieb says the Delta strain is going to continue to spread, citing new data from prominent British epidemiologist Neil Ferguson, who told reporters last week that the variant is about 60% more transmissible than the original B.1.1.7 variant first found in the United Kingdom. However, Gottlieb said the COVID-19 vaccines approved for use in the U.S. and overseas appear to be effective at containing the Delta variant, highlighting the importance of the public vaccination campaign. “The mRNA vaccine seems to be highly effective, two doses of that vaccine against this variant. The viral vector vaccines from J&J and AstraZeneca also appear to be effective, about 60% effective. The mRNA vaccines are about 88% effective,” he said, referring to the vaccines developed by Moderna and Pfizer/BioNTech. “So we have the tools to control this and defeat it. We just need to use those tools.” Gottlieb said the risk of new outbreaks is most pronounced in the parts of the country that have low vaccination rates. “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,” he said.