A child receives a flu vaccine at a clinic in Seoul, Oct. 5. Newsis

By Lee Hyo-jin

Korea should brace for an imminent "twindemic" of seasonal influenza and the coronavirus, according to medical experts, who worry that the possible double whammy of viral infections may strain the country's medical system.

While the country had avoided harsh flu seasons in the past two years thanks to COVID-19-induced precautions, an active flu season has been anticipated this fall and winter after almost all social-distancing measures, including the mandatory wearing of face masks outdoors, have been lifted.

Some experts have warned of a worse-than-usual flu season given that people haven't been building up immunity against the virus in the past couple of years, and data shows that such a scenario is likely to materialize.

In the fifth week of September, 7.1 out of 1,000 visitors to hospitals were reported to have influenza, a 45 percent surge from 4.9 in the previous week, according to weekly information form the Korea Disease Control and Prevention Agency (KDCA) data.

The agency issued an influenza warning in mid-September for the first time since 2019 and is monitoring the number of flu patients in 200 hospitals nationwide.

Chon Eun-mi, a respiratory disease specialist at Ewha Women's University Mokdong Hospital, attributed the abrupt surge of flu patients to the recent easing of mask mandate. The government has fully dropped the mask requirement outdoors since Sept. 26.

"There could be various reasons, but for one thing, people have become less cautious about COVID-19 infections after the mask compliance was lifted. The amount of gatherings seems to have returned to pre-pandemic days, creating an environment where any viruses, including the flu, can spread easily," she told The Korea Times, Sunday. "The country's flu season typically spans from November to April, but it seems to have arrived earlier."

A baby receives a flu vaccine at a hospital in Eunpyeong District, Seoul, Sept. 21. Korea Times photo by Bae Woo-han

"Timely differential diagnosis of flu and coronavirus at hospitals is important since the two diseases have some common symptoms,' she said and advised for high risks groups, especially babies and young children who have never had a flu shot to get vaccinated this year.

Beginning Sept. 21, the government has rolled out its annual flu vaccination program, under which children aged between six months to 13 years old, people aged 65 and older, as well as pregnant women are offered a free shot.

Adding to the concerns is the spread of respiratory diseases other than flu. In particular, the country is seeing an unusual surge in human metapneumovirus (HMPV) infections.

In the last week of September, 940 patients were reported to have been infected with viral respiratory diseases, 31.5 percent of whom were infected with HMPV. The disease had not been reported in the same period of last year.

"HMPV causes cold-like symptoms such as cough, fever, and runny nose. Babies aged six months to one year are more prone to the disease than adults. It can be lethal to them since it can progress to bronchitis and pneumonia," explained Chon.

She went on to say that there is currently no vaccine against HMPV, and thus prevention through proper personal hygiene and wearing face masks is highly important.