A more infectious new version of COVID-19’s delta variant is spreading fast in the U.K., accounting for about 12% of the samples gathered in the most recent government survey.
That represents a 2.8% daily growth rate for sub-variant AY.4.2 over the course of the REACT survey, from Oct. 19 to Nov. 5, the researchers said. Still, the new sub-variant seemed less likely to cause symptomatic COVID-19.
Outside researchers cautioned that it’s too early to say for sure whether the new sub-variant is really less likely to make people sick, or whether there are other factors at work. If AY.4.2 was spreading among people who were younger or in places with broad vaccine coverage, “these factors could account for the observed difference,” Simon Clarke, an associate professor in cellular microbiology at the University of Reading, said in a briefing distributed by the Science Media Centre.
About one in 20 school-aged children had the virus over the survey period. Prevalence also doubled in people over the age of 65.
