“We expect the demand for masks will continue to increase in the coming months. People may slowly realise that they will fall ill easily when they do not put on masks and masking can protect themselves and their families. After all, Hong Kong is a densely populated city.”

The Centre for Health Protection on Thursday said the peak winter flu season was expected to arrive next week. It also pointed to a significant increase in the prevalence of Covid-19, based on the viral load in sewage samples and the number of infections.

Health officials have urged the public to get vaccinated against the flu and wear masks if they are ill, interacting with people who are sick or visiting elderly homes, hospitals or crowded places.

“Based on the latest surveillance data, we soon, probably next week, may enter the flu surge period,” Dr Chuang Shuk-kwan, head of the Centre for Health Protection’s communicable disease branch, said during a press conference on Thursday.

The Post in May reported that an uptick in mask sales was observed when Covid-19 cases and the summer flu season began in early April.

According to Ding, the end of the mask mandate led to production volume dropping from about 300,000 face coverings to fewer than 100,000 per day. But in anticipation of the arrival of the flu season, the company started to ramp up production to about 150,000 masks per day beginning in October.

Customers now mostly opted for cheaper masks with a simple design, whereas during the pandemic, people preferred more colourful ones and those that offered the highest level of protection against the coronavirus.

Alex Lee Yuk-fai, the director of local mask brand Gimans Care, said his company’s sales had grown by 20 per cent in the past three months. But even the approaching flu season might not lead to a big boost to business, he cautioned.

“As the pandemic has subsided, it is not a must to wear masks,” he said. “When the habit of wearing masks has gone, it is difficult to wear them again.”

Lee said that since the pandemic ended about 90 per cent of local mask manufacturers had closed down, and Gimans Care’s sales had dropped by 70 to 80 per cent compared with its previous peak before stabilising.

The company cut its price for a box of masks from about HK$120 (US$15) to HK$60 to match the discounts offered by other shops.

“But we do foresee that as many people have quit the industry, if the demand suddenly surges, the orders for masks may be concentrated in the remaining businesses,” he said, adding the company’s face coverings were made in both Hong Kong and mainland China.

He also agreed that customers’ interest in masks with fancy designs had faded as they now preferred those without patterns.

Chong Shun-kit, 64, said the pharmacy he worked for in Causeway Bay had seen a decrease in sales by about two-thirds since Hong Kong lifted its mask mandate.

He reported selling only about 10 boxes of masks a week and even fewer Covid-19 test kits.

Sally Lee, a 25-year-old employee at a mask shop in the same area, said sales were down by about 70 per cent since the mask mandate was scrapped. But the shop was now selling about 400 to 500 each day, she noted.

Lee’s colleague also said they had noticed “a relatively high density” of people purchasing masks recently.