The variant has become the dominant strain in the U.S. and elsewhere with its increased transmissibility.
People infected with the Delta variant of COVID would go on to infect between five and eight other people on average without any measures in place, a researcher has told Newsweek. Dr. Sonja Rasmussen is a clinical geneticist in the Department of Pediatrics and Epidemiology at the University of Florida who has studied COVID-19 throughout the pandemic. Speaking about the Delta variant, she said its increased transmissibility is part of the reason the COVID mutant is causing so much concern around the world. One way of measuring just how easily Delta can spread between people is by looking at its R0 number, or reproductive number. This number refers to how many people an infected person can expect to spread the virus to if there were no measures in place to prevent this, and it differs between variants. According to The Lancet medical journal, the reproductive number of the original strain of COVID was around 2.5. The Alpha variant was then around 60 percent more transmissible than this. Delta is thought to be about 60 percent more transmissible again, resulting in a reproductive number that could be as high as R8, said Rasmussen.