The city has recorded at least 405 related deaths in the flu season so far, which included four children, with severe cases hitting new highs.
Last week, a six-year-old boy died after contracting influenza A and developing complications from brain lesions.
Six patients aged 58 to 94 were also infected at Sha Tin Hospital’s geriatric ward, with one in a severe condition due to an existing illness.
Health authorities earlier warned the seasonal influenza outbreak would remain at a high level for an extended period.
Hui said the number of influenza A infections was still on the rise and showed no sign of easing.
He suggested that the current winter season was likely to extend to the approaching summer spike.
“Before the pandemic, we had a flu outbreak between January and March, which lasted 10 to 14 weeks,” he explained.
“It would reach its peak in the first four to six weeks and drop to the baseline between week six and week eight.
“But infections this year haven’t stopped since the second week of the year.”
The respiratory specialist called on parents to seek medical attention swiftly if their children caught the flu, as a delay in treatment would increase the risk of potentially fatal complications.
“We have found that if severe cases can receive prescriptions of Tamiflu within 48 hours, the mortality risk can be reduced by 80 per cent,” he said, referring to an antiviral medication used to treat and prevent influenza.
“If you were prescribed Tamiflu within three to five days of illness, the risk of death can still be reduced by 65 per cent.
“But if the prescription is given more than five days following the onset, the effect will not be as ideal.”
Hui attributed the persistent rise in infections to the long duration of the city’s mask mandate during the coronavirus pandemic, which stopped residents from being exposed to other pathogens and ultimately decreased their immunity.
“We had worn masks for the past three years and not been exposed to influenza viruses for a long time, so we have lost the resistance,” he said.
He also advised residents to get vaccinated as soon as possible.
“Only 47.7 per cent of those between six months old and five years old have received a flu shot,” he said.
“The vaccination rate is about 51 per cent for another vulnerable group, which is those aged 65 or above.
“Both groups are more likely to develop severe cases or complications after infection, so we must try our best to vaccinate them.”
He stressed that even if residents got infected after vaccination, the risk of complications could still be effectively reduced.