The Centre for Health Protection said today it is probing three additional imported COVID-19 cases involving the L452R mutant strain.

The patients arrived from the Philippines, Thailand and Saudi Arabia. Two of them tested positive during quarantine and the remaining one tested positive at the airport.

Regarding cases 12376 and 12378 involving two Hong Kong-based cargo flight crew reported yesterday, the whole genome sequencing analysis done by the University of Hong Kong showed that both of them had a Delta strain with highly similar but not identical genetic sequences.

They belong to the Delta strain sub-lineage AY.43, a strain which is common in Europe, especially Germany.

Meanwhile, the centre is following up on the epidemiological investigations and genetic sequencing of case 12379 to rule out its linkage with the above cases.

The genetic sequences of these three cases were not related to other previously confirmed cases in Hong Kong. The results suggest that cases 12376 and 12378 acquired the infection outside Hong Kong, while case 12379 previously acquired the infection outside the city and is classified as an imported re-positive case.

In addition, the centre continues to follow up on all imported cases involving mutant strains by conducting whole genome sequencing to identify the lineage of the variant strains.

According to the latest sequencing analysis conducted by the centre's Public Health Laboratory Services Branch, the virus strain of imported case 12374 matched the Delta strain sub-lineage AY.4.2.

Case 12374 travelled to Hong Kong on November 1 on the same flight BA027 as imported case 12357, whose virus strain also matched sub-lineage AY.4.2 as announced on November 5. Their seats were close to each other. The centre's epidemiological investigation is ongoing.

The Government announced on October 26 that patients fulfilling the discharge criteria have to be immediately arranged by point-to-point transfer to designated isolation facilities to undergo the 14-day isolation and health monitoring through a close-loop management arrangement.

From today, Dorsett Kwun Tong Hotel will replace the North Lantau Hospital Hong Kong Infection Control Centre as the designated isolation facility. The Department of Health arranged a total of 37 discharged patients to the hotel to complete their remaining isolation today.

The centre reminded specified people in relation to Harbour Pinnacle in Tsim Sha Tsui to undergo testing tomorrow in accordance with the compulsory testing notice.

Eight schools are covered in the latest compulsory testing notice due to outbreaks of upper respiratory tract infection or influenza-like illness.

The Government will set up a mobile specimen collection station at 15-17 Mody Road in Tsim Sha Tsui tomorrow to provide free testing services for residents and workers of Harbour Pinnacle subject to compulsory testing. Another station at the open area next to Discovery Bay Fire Station will also continue to operate tomorrow.

There were 39 cases reported in Hong Kong in the past 14 days, all of which are imported.

For information and health advice on COVID-19, visit the Government's dedicated webpage.