Explainer | What you need to know about the mutant coronavirus strains in Hong Kong

This story has been made freely available as a public service to our readers. Please consider supporting SCMP’s journalism by subscribing. Hong Kong has detected its second locally transmitted Covid-19 case involving a mutant strain, raising concerns about its circulation within the community. Health officials, meanwhile, have also warned of a potential surge in cases while an ongoing investigation into the source of the two infections is under way. Below, the Post unpacks what you need to know about the mutant coronavirus strains found in Hong Kong. What are the major variants of the coronavirus detected in Hong Kong? Hong Kong has so far detected three major coronavirus variants bearing the N501Y mutation, which are known to be more infectious than the original strain. The variant from Britain is believed to have emerged last September, and was first detected in Hong Kong in late December after two students returned from there. It is also the variant accounting for the most cases involving mutated strains in Hong Kong. Officials have also detected cases with variants from South Africa and Brazil. How did Hong Kong’s first local variant case come about? A total of 223 cases involving mutated versions of the coronavirus have been detected in Hong Kong, but until Friday, all of them had been imported, according to the Department of Health, and none had made their way into the community. The city confirmed its first local case involving a variant on Saturday: a 29-year-old man who worked in Dubai as an engineer. The asymptomatic patient returned to Hong Kong on March 19, and completed his mandatory 21 days of quarantine at the Ramada Hong Kong Grand Hotel in Tsim Sha Tsui on April 8. He then went to stay at his friend’s place in the Parkes Building, located at 17-23 Parkes Street in Jordan, and later visited several other places, including Chungking Mansions in Tsim Sha Tsui and Cheung Chau island. It was only when he was preparing to go back to Dubai that he took another coronavirus test on Thursday. BioNTech vaccine should be effective in protecting against certain Covid-19 strains: experts His friend, a 31-year-old woman, was also confirmed to be infected with the mutant strain on Sunday while staying at a government quarantine facility. She did not have any travel history, according to health authorities. Officials are still trying to track the source of the man’s infection. How has the local government stepped up prevention measures? Hong Kong announced on Sunday a two-week travel ban on people coming to the city from India, Pakistan, and the Philippines, classifying those areas as “extremely high risk”. The order takes effect on Tuesday. Authorities have also imposed their “toughest infection-control measures” in light of the variant cases, quarantining about 80 residents at Parkes Building for 21 days – up from the normal 14. Although an overnight lockdown and mandatory testing did not find other positive cases there, authorities determined the risk of infection was “likely higher than usual” as subdivided flats were common in the relatively old building. Are current vaccines effective against the variants? According to the government, the BioNTech vaccine is believed to be effective against the British and Brazilian variant strains, but may be less so when it comes to the South African one. There is currently limited data on the efficacy of Sinovac vaccines against variants, but the company is currently conducting more studies into the matter in Brazil. How are other countries dealing with Covid-19 variants? In the United States, President Joe Biden’s administration plans to allocate US$1.7 billion toward tracking Covid-19 variants, as about half of all the country’s Covid-19 cases have been attributed to such strains. The funds aim to “improve the detection, monitoring, and mitigation of these COVID-19 variants” to fight the mutations more effectively. Meanwhile, the European Commission will mobilise €123 million (US$147 million) from Horizon Europe, a new EU research and innovation programme, for urgent research into coronavirus variants. What can you do to protect yourself from Covid-19 variants? For starters, the public can join the city’s vaccination programme, experts say. “For the general public, they should really join the vaccine programme as soon as possible. Once the variants enter the community in Hong Kong, it is actually much more infectious compared to the non-variants,” said government adviser and respiratory medicine specialist David Hui Shu-cheong. Hui also said people ran the risk of reinfection if they were not vaccinated. “If someone was infected with the non-variant in the past, the antibody levels in the blood may not neutralise the variant, so there’s risk of reinfection. So I think they should build up immunity as soon as possible.”