30,000 Cases Detected of AY.4.2. COVID Variant That Could Spread Faster Than Original Delta

More than 30,000 cases of the AY.4.2 COVID variant have been detected worldwide, according to tracking data.

AY.4.2 is an offshoot of the Delta variant AY.4, meaning it is a variant of a variant of Delta.

It is marked by two mutations called Y145H and A222V that affect AY.4.2's spike protein, which is what the virus uses to enter human cells.

Researchers took note of AY.4.2 last month after data showed the variant was spreading around the U.K., accounting for a growing percentage of new cases.

According to Outbreak.Info, which collects data on the spread of COVID variants using a virus reporting network called GISAID, AY.4.2 accounted for between 13 and 14 percent of new coronavirus samples that were sequenced in the U.K. as of November 8. That figure has been growing since July.

The variant does not appear to be spreading as fast in the U.S., where, according to the same data, there have been a total of 28 cases reported from 11 states.

Worldwide, there had been 32,004 AY.4.2 cases reported from 37 countries, Outbreak.Info showed on November 8.

Figures on AY.4.2 may have changed significantly since late last month due partly to reporting fluctuations, which GISAID has acknowledged.

Last month, the U.K. Health Security Agency (HSA) noted that growth rates for AY.4.2 are estimated to be slightly higher than for other Delta variants. Some scientists had already pointed out that the variant appeared to be more transmissible than its ancestors.

The HSA noted that according to preliminary analysis, AY.4.2 did not show any significant increase in vaccine resistance compared to other Delta variants. More testing is needed to confirm this.

AY.4.2 has been classified as a "variant under investigation" in the U.K., with the label VUI-21OCT-01.

U.S. officials acknowledged the variant in a White House press briefing on October 20, in which Centers for Disease Control and Prevention (CDC) director Rochelle Walensky said the sub-variant had been detected "on occasion" in the country, "but not with recent increased frequency or clustering to date."

She added: "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."

According to the World Health Organization, just under 250 million confirmed cases of COVID-19 had been reported worldwide as of Monday afternoon along with 5,047,652 deaths. 7 billion vaccine doses had been administered.

COVID swab
A health worker holds a COVID swab and sample collection tube in Lombardy in March 2020. Over 30,000 COVID AY.4.2 sequences have been detected worldwide. Miguel Medina/AFP / Getty