A top epidemiologist has urged Hong Kong to lift flight bans and allow residents to return to the city since the risk of local Covid-19 transmission now exceeds that posed by imported cases, as officials reported record numbers for the daily caseload and coronavirus-related deaths. Professor Gabriel Leung, dean of the University of Hong Kong’s (HKU) faculty of medicine, on Thursday also said the city should ramp up vaccinations among children before classes resumed in April to prevent yet another Covid-19 wave from emerging. He made the warning with Hong Kong logging 17,269 “reported infections” as of Wednesday night, referring to all cases collected from public and private facilities across the city on a particular day. There were also 8,798 new Covid-19 cases confirmed on Thursday, taking the official tally to 84,046. The Hospital Authority reported 50 new fatalities, involving patients aged 52 to 97, with only six of them having received two doses of a Covid-19 vaccine . Another 17 people, aged between 68 and 93, died earlier but the cases were only reported on Thursday due to a backlog. The city’s Covid-related death toll is now 470. Thirty-three patients are in a critical condition, while 49 are in a serious condition. A chronically ill nine-year-old boy who was found unconscious at home on Wednesday night was admitted to United Christian Hospital and died the following morning. He was unvaccinated and tested positive for the virus. Consulates in Hong Kong concerned by separation of parent from Covid-positive baby Health officials said the boy was diagnosed with a genetic disease when he was a toddler. He had no upper respiratory tract infection symptoms, fever, or convulsions. He did not have contact with Covid-19 patients or test positive prior to admission. The case will be referred to the coroner for investigation. The authority said the boy’s death will be counted in Friday’s figure. Professor David Hui Shu-cheong, a government adviser on the city’s Covid-19 vaccination drive, said if the boy’s death was found to be related to the virus, it would be further proof that unvaccinated children with Covid-19 were more prone to symptoms or death. “If you are unvaccinated, it is very likely that your condition will deteriorate. With chronic illnesses, it is even more likely that complications will develop. That is why we are asking children to receive vaccines as soon as possible,” he said. “Their immune systems are not mature enough and incapable of battling the virus.” Leung, meanwhile, said that while it was “very suitable” to implement flight bans in the past when local cases were practically non-existent, the risk assessment had changed amid the current wave of infections. “Every day we are seeing thousands of cases … I cannot see any good reason to ban residents stuck overseas,” he said, adding that travellers should still be required to test negative prior to departure and quarantine at designated hotels for two weeks. “If they do that, their risk of spreading the disease is lower than those living in Hong Kong right now. Given that we already have a huge outbreak, we should use this opportunity and allow them to come back, because they cannot change our risk level. In fact, allowing them to return after we have cleared infections would be riskier.” The government on Tuesday extended existing flight bans on nine countries until at least April 20. The countries are Australia, Britain, Canada, France, India, Pakistan, Nepal, the Philippines and the United States. Authorities also brought forward students’ July-August summer holiday to March-April so schools could be used as testing, isolation and vaccination venues when compulsory universal Covid-19 testing is carried out next month. According to mathematical modelling by public health experts at HKU, the fifth wave should peak between the first and second week of March, then gradually fade away in late April. Leung said he believed the universal testing campaign next month would hasten the fadeout. He urged the government to set up more vaccination centres for children with the goal of boosting their inoculation rate to 90 per cent before in-person classes resumed in April. He also said more centres administering the German-made BioNTech vaccine were necessary, as it offered stronger protection for children. “We only have eight to 10 weeks to do it,” he said. “There are tens of thousands of pupils in Hong Kong but we only have three centres for BioNTech vaccination, which means only 60,000 pupils can be inoculated in 30 days.” Based on other countries’ experiences with Omicron waves, Leung said, the resumption of face-to-face classes was often followed by another “mini wave” of infections. “We must protect the entire community from another wave of infections just as the fifth wave is fading out when classes resume,” he said. To boost the inoculation rate and overall protection for the community, Leung said the Centre for Health Protection’s joint scientific committee should discuss whether it was necessary to wait three months between the first and second vaccine doses, and consider allowing those aged between 12 and 17 to receive a booster shot. Hui said the period between the first and second BioNTech doses should not be too short, as it might expose children to a high risk of myocarditis, an inflammation of the heart muscle. He suggested that eight weeks would be acceptable. “We took reference from places like Canada and realised if there is an eight- to 12-week interval between the two doses, the risks of having myocarditis will be reduced,” he said. Leung also urged the public not to calculate the Covid-19 death rate by themselves, saying it was not “a simple division exercise”. “You cannot divide today’s registered number of deaths by the cumulative number of reported cases today. It is wrong. If you do that you risk either scaring yourself or falsely reassuring yourself,” he said, warning also of an “inherent bias”. He added that it took three weeks to calculate the fatality rate during the severe acute respiratory syndrome (Sars) outbreak in 2003. Leung asked the public to be patient with the Department of Health as they were still grasping with calculations and the total number of infections, which might be 10 times that of reported cases. He said this might be due to asymptomatic cases, people who choose not to report positive results to the government, as well as testing backlog. Separately, all 300 beds at Tin Shui Wai Hospital will be used for treatment of Covid-19 patients starting on Saturday. The authority previously announced that non-Covid-19 patients undergoing rehabilitation and services such as radiotherapy and dialysis would be transferred to private hospitals in a bid to ease the pressure on public facilities. Under the scheme, 12 and 20 beds at Hong Kong Baptist Hospital in Kowloon Tong and St Paul’s Hospital in Causeway Bay are available for use.