Is COVID-19 like the flu?

Perhaps one of the most frequently posed questions since the pandemic’s onset is how the new virus may compare to seasonal influenza.

Infectious disease specialist Dr. Oh Myoung-don, who leads the National Medical Center’s committee for clinical management of emerging infectious diseases, said during a press conference Tuesday that complications from “COVID-19 might not be more severe than the flu.”

“Certain cardiovascular and neurological complications have been associated with COVID-19. But the same could be said for the flu,” he said. “In fact, more recent data shows complications or long-term effects of COVID-19 aren’t as serious as those of the flu.”

In making his assessment, Oh cited findings from a Nov. 13 study published in the journal Science Advances.

The study said COVID-19 patients had less inflammation than influenza patients. Out of the 168 patients with COVID-19 the study looked at, only seven exhibited a potentially fatal immune response known as cytokine storm.

Oh clarified in a later exchange with The Korea Herald that his statement is “not intended to be interpreted as though COVID-19 is not more dangerous than the flu.” 



COVID-19 is not ‘just the flu’
 

Many health experts say COVID-19 and the flu aren’t equivalent.

Respiratory disease specialist Dr. Chun Eun-mi of western Seoul’s Ewha Womans University Medical Center said the coronavirus is less virulent than initially thought, but it is still much deadlier than influenza.

“In Korea, the fatality rate for COVID-19 stands at around 1.67 percent. The rate for flu is estimated to be less than 0.1 percent,” she said.

Besides, there are effective antivirals against flu and rapid diagnostic tools to detect and treat the infection early that can reduce the risks of severe outcomes. “Whereas with COVID-19, the treatments are still to come,” she said.

“Without a treatment available, the chances of coming down with severe disease are higher if a person has COVID-19.”

Another respiratory disease specialist, Dr. Han Chang-hoon of National Health Insurance Service Hospital in Ilsan, Gyeonggi Province, said young and healthy people should be reminded that “they, too, are capable of getting seriously ill or dying from COVID-19.”

“Young people are told to follow precautions to protect those who are more vulnerable. Which is true, but it’s also to protect themselves,” he said. “There haven’t been many cases of severe COVID-19 among young people in Korea so far. But if the virus continues to surge, we might start seeing such cases.”

Infectious disease specialist Dr. Kim Woo-joo of Korea University Medical Center in Guro, southern Seoul, said COVID-19 “is not ‘just the flu.’”

“Flu comparisons are often made to downplay the perils of COVID-19, and I think such messaging can have potentially dangerous consequences,” he said.

COVID-19 has a longer incubation period, higher infectivity and greater lethality than the flu in most age groups with the exception of children, he said. “But these are only part of the characteristics that sets the coronavirus apart from the influenza.”

One of the other reasons that COVID-19 calls for more wariness is the aberrant ways that it manifests.

Unlike normal pneumonia, the pneumonia caused by COVID-19 can be difficult to detect as some patients do not experience noticeable breathing difficulties. “This condition is known as ‘silent hypoxia,’ which is when patients who do not appear to be short of breath are actually in worse health,” he said.

“Long COVID,” which refers to the long-term effects among some former patients, is another example of an unexpected phenomenon linked to the disease.

“We still don’t know enough about COVID-19 to speak definitively about it,” he said.



COVID-19 vs. flu
 

Dr. Jerome H. Kim, the director general of the International Vaccine Institute, said during a lecture at the Moroccan ambassador’s residence in Seoul on Tuesday evening that while symptoms of COVID-19 and flu overlap, there were key disparities.

“Common flu symptoms include fever, cough, runny nose, fatigue, muscle and body aches. All of those symptoms are present in COVID-19. One thing that may distinguish COVID-19 is this loss of a sense of taste or smell,” he said.

For both COVID-19 and flu, there are people who never develop symptoms. This is known as asymptomatic infection.

“About 80 percent of people with COVID-19 are mildly symptomatic or asymptomatic. Fifteen percent of people are hospitalized. Five percent are put on ventilators, so machines can help them breathe. One to 2 percent die,” he said.

If people have COVID-19, it can take longer for them to develop symptoms than if they had the flu.

“The incubation period for COVID-19 is usually four to five days. Influenza’s incubation period is slightly shorter,” he said.

COVID-19 is also much more contagious than the flu, but they spread in similar ways.

“A very striking difference is in the transmissibility. Basically, COVID-19 spreads from person to person more efficiently than the standard flu,” he said. “If you have influenza, you might transmit that infection from 1.4 to 1.6 people. With COVID-19, you could transmit that to two to six people.”

Another thing that characterizes COVID-19 is what we call superspreader events, he added. “You hear stories of a single infected person leaving almost over 90 percent of the people in the same room infected.”

COVID-19 transmission takes place through exposure to respiratory droplets, much like the flu.

“So typically, you’re safe (from COVID-19) if you’re more than a meter away. But there is some aerosolization, which is actually more dangerous because the viral particles can drift in the air and travel meters before settling,” he said. “Respiratory droplets are also how influenza transmits, although there’s dispute now over whether it can be transmitted by aerosols.”

By Kim Arin (arin@heraldcorp.com)