A new SARS-CoV-2 variant has emerged—AY 4.2, which is a sub-lineage of the Delta variant, Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky, MD, MPH, said at a news briefing of the White House COVID-19 Response Team.
CDC is continuing to track lineages and sub-lineages of Delta and all other variants. Over the past nine months, as we have previously reported, we have ramped up our sequencing capabilities in partnership with local public health and academic institutions. We particularly monitor for sub-lineages that could impact therapeutics, such as monoclonal antibodies and vaccines.
“The AY 4.2 variant has drawn some attention in recent days,” Walensky said, adding that it has been identified in the United Kingdom. “And we have on occasion identified the sub-lineage here in the United States, but not with recent increased frequency or clustering to date.”
Over the past nine months, the CDC has partnered with academic institutions and public health departments to track sub-lineages of SARS-CoV-2 variants, Walensky said. “At this time, there is no evidence that the sub-lineage AY 4.2 impacts the effectiveness of our current vaccines or therapeutics, and we will continue to follow up.”
Meanwhile, UK Health Security Agency confirmed in a recent report that AY 4.2 is expanding in England, and the agency is now monitoring the variant.