Covid-19’s Mu strain has not hit Hong Kong though three people tested positive for the latest mutation of the virus, government adviser David Hui Shu-cheong says.
But Ho Pak-leung, director of the Centre for Infection at the University of Hong Kong, warned that if Mu spread further in Europe and the United States then imported cases elsewhere would also increase.
The warning was issued as Lohas Park Le Prestige’s Tower 2, Phase 2A in Tseung Kwan O was cordoned off at 7pm yesterday after a 42-year-old woman living there tested positive for Covid-19 following her return from the United States on Sunday.
All residents must undergo tests before 1am today and the lockdown is expected to end by 7am.
Hui, a respiratory medicine expert at Chinese University, said there were three imported cases that involved Mu, which was first found in Colombia in January.
But none of the three developed Covid symptoms and they did not have to undergo antiviral treatment.
The latest case was a 26-year-old student who arrived from the United States on July 20 and was discharged on August 3.
“All three patients tested positive during quarantine and were sent to public hospitals,” Hui said. “Therefore, the variant has not entered the local community.”
Hui said Mu appeared to reduce the efficacy of vaccines as the student had completed two doses of BioNTech jabs in May before going to the United States.
If a mutant virus is involved, he added, anyone could get infected.
“The term ‘herd immunity’ no longer applies as getting vaccinated does not mean people will not be infected,” Hui said. “[It should be] ‘herd protection’ as vaccines can reduce the risk of serious illness and death.”
The Mu variant was added to the World Health Organization’s list of “variants of interest” on August 30 because it has the potential to evade antibodies, Hui explained.
It is not yet classified as a “variant of concern” as with the highly contagious Delta, first discovered in India, or Alpha from the United Kingdom, Beta from South Africa and Gamma from Brazil.
Although Mu is known to be in 39 countries, the global infection rate is less than 0.1 percent, Hui said.
He said it seems to be less infectious than Delta, but there is not enough data at this stage.
HKU’s Ho said more than 5,000 cases of Mu have been recorded worldwide, including around 2,200 in the United States and 900 in Colombia.
It would not be surprising to see people traveling from those countries to Hong Kong testing positive for Mu, Ho said.
Cases involving Mu have also been rising slightly recently in some European countries, and that could also lead to more imported cases in Hong Kong.
Ho said it is not a good time to allow domestic helpers from the Philippines to travel to Hong Kong as their country is suffering from a severe pandemic situation. It recorded its highest daily count of 22,415 new cases yesterday. A few cases, he added, could be expected on every plane from the Philippines landing in Hong Kong.
But Indonesian helpers could be welcomed, Ho added, because the virus in their country has been under control recently.
Indonesia reported 5,403 new cases and 392 more deaths on Sunday.
Hong Kong recorded two imported cases from Indonesia and the United States yesterday, taking the city’s tally to 12,124 infections with 212 deaths.
The Indonesian is a 23-year-old female domestic helper who received two Sinovac shots in Hong Kong on March 7 and April 6.
The other case involved a 20-year-old US man who had two BioNTech jabs in America. He was carrying the L452R strain.
Meanwhile, the government said it will recognize vaccination records issued by India, Malaysia, Pakistan, Thailand and South Korea authorities starting tomorrow.