BA.5 may become main strain in HK

August 7, 2022

Centre for Health Protection Communicable Disease Branch Head Dr Chuang Shuk-kwan:

Taking reference from the WHO (World Health Organization), Singapore and other places, we understand that there is a growth advantage of the BA.5 (Omicron subvariant) over other subvariants. 

We cannot exclude the possibility that BA.5 will further increase in proportion and become the circulating strain in Hong Kong.

We understand that BA.5 has a higher transmissibility. But fortunately, we do not have any evidence that this strain is more severe (in nature) or would cause more deaths.

Also, the current evidence shows that the current (COVID-19 vaccines are) still effective against this strain in preventing severe illness and death. So I would take this opportunity to urge people who have not yet completed their vaccination to receive it as soon as possible.

(To watch the full press briefing with sign language interpretation, click here.)

The Centre for Health Protection today said it is investigating 4,035 additional locally acquired COVID-19 cases, adding that it cannot rule out the possibility that Omicron subvariant BA.5 will become the circulating strain in the city.

The centre's Communicable Disease Branch Head Dr Chuang Shuk-kwan told a press briefing this afternoon that the BA.4 and BA.5 subvariants account for about 10% of all local cases.

“Taking reference from the World Health Organization, Singapore and other places, we understand that there is a growth advantage of BA.5 over other subvariants.

“We cannot exclude the possibility that BA.5 will further increase in proportion and become the circulating strain in Hong Kong.

"We understand that BA.5 has a higher transmissibility. But fortunately, we do not have any evidence that this strain is more severe (in nature) or would cause more deaths.”

However, Dr Chuang stressed that the current scientific evidence shows that the COVID-19 vaccines available at the moment are still effective against the BA.4 or BA.5 strain in preventing severe illness and death.

Among the additional local cases, 1,410 were directly identified through nucleic acid tests and 2,625 via verified rapid antigen tests. Separately, 239 imported cases were reported.

Meanwhile, a kindergarten has been advised to suspend face-to-face lessons for a specific class for one week.

Furthermore, three residential care homes reported infections involving residents.

The centre added that five more patients passed away.

Due to a number of positive cases, 51 specified places are included in a compulsory testing notice. It also covers five specified premises in Ma On Shan, Kwai Chung and Tsuen Wan where some sewage samples tested positive for the virus.

The Government will set up or reopen mobile specimen collection stations at Ap Lei Chau Estate in Southern District and Bellagio in Sham Tseng tomorrow. The mobile station at Wah Fu (II) Estate in Pok Fu Lam will extend its service to August 9.

As there were positive sewage test results with relatively high viral loads in several buildings of Wan Chai, Kwun Tong, Yuen Long, Eastern and Southern districts, the Housing Department and respective district offices will distribute COVID-19 rapid test kits to relevant residents as well as cleaning workers and property management staff working there.

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