First cases of Delta variant strain AY.4.2 detected in B.C.

The first cases of the Delta variant strain AY.4.2 have been detected in B.C.

Originally detected in the United Kingdom, Delta AY.4.2 was designated a Variant Under Investigation (VUI) by the UK Health Security Agency (UKHSA) on Oct. 20. 

The strain was given this designation because it became increasingly common in the United Kingdom in recent months, and "there is some early evidence that it may have an increased growth rate in the UK compared to Delta," explains a news release. 

Provincial health officer Dr. Bonnie Henry told reporters in a press briefing Tuesday (Nov. 16) that there are now about 120 sub-lineages of the Delta strain around the world. 

"All viruses mutate and we know that," she explained. "Development of these new lineages which are unique to geographic areas are really expected over time when we have ongoing transmission in our communities."

AY.4.2. has not been designated a variant of concern (VOC) yet in B.C., but health officials continue to monitor its development locally. 

"What we are looking for is whether these variants of interest and concern are spreading more quickly, or making people sicker. And of course, we're watching very carefully to see if they're associated with less effectiveness of the vaccine," she said, adding that strains of the Delta variant spread much faster and cause more severe illness in younger people. 

The first cases of AY.4.2 have been detected in the Fraser Health Region and health officials are doing contact tracing to see where the individuals might have acquired it.

While health officials In Europe haven't noticed that the strain causes reduced effectiveness against vaccines, Henry noted that they have seen "slightly increased transmissibility." 

The numbers of new infections, active cases, and COVID-19 patients in B.C. hospital intensive care units all fell again today. Perhaps most importantly, the number of those who are dying from the disease appears to be tracking down. 

B.C. reported that health officials had detected 338 new COVID-19 infections in the past day, with that being the lowest number since November 1, when there were 332. 

— With files from Glen Korstrom.