A second round of novel coronavirus infections could coincide with the return of seasonal flu in fall, South Korean health authorities said Thursday, and that greater influenza vaccination will be “one of the most essential interventions” in fending off the double risk of contagion.

Korea Centers for Disease Control and Prevention’s Deputy Director Kwon Jun-wook said in a press briefing Thursday afternoon that flu vaccination was projected to be “more critical than ever” this coming fall and winter due to possibility of COVID-19 and other seasonal illnesses with similar symptoms arriving at the same time.

“A flu shot can make telling apart the COVID-19 from influenza easier for health professionals,” he said. “Not only that, the flu virus is forecast to circulate more widely this year than the last.”

The disease control agency believes at-risk groups aged 60 or older “absolutely need to get vaccinated” against flu for the 2020-21 season, he said.

Yoon Tae-ho, the Health Ministry’s public health policy director, said in a press briefing earlier the same day that the ministry was considering making the influenza vaccination compulsory for a wider range of the population to get more people immunized against flu.

The idea is to protect as many people as possible against seasonal flu and hopefully make co-circulation of the two viruses less challenging, he said.

“The government is working with drugmakers to produce sufficient doses of influenza vaccine to prepare for an uptick in the number of people getting vaccinated.”

Speaking at a conference at the National Assembly, preventive medicine specialist Dr. Ki Moran of National Cancer Center said the next wave of COVID-19 turning out to be deadlier than the first was “highly conceivable.”

“Second wave of the Spanish Flu in fall of 1918 killed five times more people than the first,” she said. “If history is any guide, a more expansive vaccination program has to be put in place nationwide to brace for fall and winter.”

“Around 20 million got the annual seasonal flu vaccine last year. This year, the coverage should be raised to at least 30 million,” Ki said, adding that the vaccines should be given free of charge to people with preexisting medical conditions, health care workers and other workers whose jobs involve a lot of person-to-person interactions.

Ki also pointed out falling ill with both COVID-19 and the flu was “an unfortunate possibility.”

An article that appeared in the Lancet medical journal on May 5 said co-infection by both viruses -- the coronavirus and the influenza -- though rare, was feasible.

“Those vulnerable from COVID-19 are also at increased risk from flu, which is why increased efforts are necessary to deliver flu vaccination more extensively,” said infectious disease expert Dr. Lee Jacob of Seoul’s Hallym University Hospital.

By Kim Arin (arin@heraldcorp.com)