Hong Kong's Center for Health Protection (CHP) confirmed on Friday that the virus strain of a recent imported COVID-19 case matched the Delta strain sub-lineage AY.4.2, a newly designated sub-lineage of the Delta strain.
According to the World Health Organization, an increase in AY.4.2 viruses has been observed globally since July this year and over 26,000 AY.4.2 sequences from 42 countries and regions had been uploaded to the online genome database GISAID by the end of October. Ninety-three percent of these sequences were reported from Britain, where a gradual increase in the proportion of AY.4.2 has been observed.
It was reported that AY.4.2 might be more transmissible than other Delta strains, the CHP noted.
The CHP said that follow-up investigations will be conducted on all imported cases involving mutant strains in Hong Kong to identify the lineage of the variant strains, including sub-lineage AY.4.2.
Meanwhile, the CHP on Friday reported one new imported case of COVID-19, taking the tally in the financial hub to 12,360.
A total of 48 cases have been reported in the past 14 days and all of them were imported, according to the CHP.
Hong Kong's vaccination drive is making steady progress. Since the launch of the government inoculation program in late February, more than 4.63 million people, or 68.8 percent of the eligible population, have taken at least one shot of the vaccine, while around 4.44 million are fully vaccinated.