A new coronavirus variant, first identified in the United Kingdom, has been observed in the United States, the CDC said.
The AY4.2 strain is a sub-lineage of the more infectious delta variant, which recently swept across the United States and dramatically boosted infections and deaths in the South.
UK health experts worry that the new strain is reportedly 10 to 15 more infectious than the delta variant, the New York Post reported. A small but growing number of coronavirus cases in the UK, roughly 6%, are AY4.2 infections, according to the country’s Health Security Agency.
“There are new variants that continue to emerge as cases continue to spread,” said Dr. Rochelle Walensky, director of the CDC, during Wednesday’s COVID-19 briefing. “And in particular, the AY4.2 variant has drawn some attention in recent days.”
CDC genomic sequencing said less than 1% of identified coronavirus cases came from the sub-lineage strains, with 99% of U.S. coronavirus cases coming from delta infections.
“At this time, there is no evidence that the sublineage AY4.2 impacts the effectiveness of our current vaccines or therapeutics,” Walensky said, “and we will continue to follow.”
Former U.S. Food and Drug Administration commissioner Scott Gottlieb took to social media to spread his concerns about the spike in UK cases and how the new strain may be driving cases.
“We need urgent research to figure out if this delta plus is more transmissible,” he tweeted. “The variant has been in the UK since about July, but it has been slowly increasing in prevalence. There’s no clear indication that it’s considerably more transmissible, but we should work to more quickly characterize these and other new variants.
“This is not a cause for immediate concern but a reminder that we need robust systems to identify, characterize new variants,” he concluded.
Experts are cautious but not alarmed. “Delta is incredibly good at transmitting in a vaccinated population and a new one may be a bit better but it’s unlikely to change the picture dramatically from where we are today,” Oxford Vaccine Group chief Andrew Pollard told the BBC.