Hong Kong has seen a rise in COVID-19 cases in recent weeks, with the positivity rate reaching a one-year high of 13.66 percent, up from 6.21 percent a month ago.

Health officials are urging the public to stay alert, strengthen personal hygiene, and get vaccinated promptly, particularly those who have not yet received their initial doses.

In a statement by the Centre for Health Protection issued on Thursday, 81 severe adult cases and five severe pediatric cases were recorded in the past four weeks, with 30 deaths.

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The health authority noted that COVID-19 has evolved into an endemic disease in Hong Kong, with active cycles occurring every six to nine months due to shifts in dominant variants and waning population immunity. The last two waves in 2023 and 2024 lasted 15 and seven weeks, respectively.

CHP Controller Edwin Tsui Lok-kin said that the XDV variant has become the dominant strain in Hong Kong since late March, while there is no evidence suggesting XDV causes more severe illness.

“Eighty-three percent of the severe adult cases were persons aged 65 or above, and more than 90 percent of these elderly cases had underlying illnesses. Only one case had received a booster dose of the COVID-19 vaccine in the past six months,” the CHP’s statement said.

Tsui expressed concern over low booster vaccination rates among elderly residents, estimating that 90 percent of the elderly within the community have not received a COVID-19 booster.

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For children, the CHP has recorded five severe cases, none fatal, so far this year. Of those, two had underlying illnesses and three had not received any dose of the COVID-19 vaccine.

Tsui said this shows that even children who are in good health can experience severe complications from COVID-19 infection, and urged those in high-risk groups and children — especially those with underlying illnesses — to receive an additional booster dose as soon as possible.

"We will continue monitoring virus mutations in line with the World Health Organization guidelines to detect any future variants with higher virulence or vaccine evasion potential," he said.

Respiratory specialist Leung Chi-chiu told China Daily that there is no need for excessive concern about the endemic, noting that the present circulating strain is not the newest variant and has already been widely observed in regions including the Chinese mainland, presenting relatively low health risks.

However, he specifically recommended that high-risk people and children aged under 1 to 2 years old should receive the vaccine to enhance immunity.

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Addressing concerns among mainland tourists worried about potential infection risks in Hong Kong, Leung gave his assurances that such worries were unnecessary.

"Given the frequent population exchanges between the two places, our epidemic patterns have become synchronized," he explained.

Leung projected that infection numbers would gradually decline within three to four weeks. However, he cautioned that even after passing the peak period, it would still take some time to rebuild population immunity.

Contact the writer at stacyshi@chinadailyhk.com