President Donald Trump drew a direct comparison between the seasonal flu and the new coronavirus in his first press conference on Covid-19, saying that Americans might have more to fear from flu than the headline-making virus.
But a closer comparison of the two viruses creates a more worrisome picture of what could happen if Covid-19 virus becomes widespread in the United States, infectious disease experts say.
The new coronavirus is more infectious than the flu and appears to strike with much higher severity in certain vulnerable groups.
At the same time, there are no treatments on hand for Covid-19 as there are for the seasonal flu, experts added.
In line with pandemic flu strains
Initially, estimates on the death rate in China hovered around 2%, but a report published last week in the New England Journal of Medicine arrived at a death rate of 1.4%. And leading health experts wrote in an accompanying editorial that many mild cases have been missed, driving the death rate down closer to around 1%.
The death rate associated with a typical flu season is around 0.1%, according to the US Centers for Disease Control and Prevention.
The apparent death rate of the new coronavirus is more in line with pandemic flu strains, where a new mutation causes the flu virus to become more contagious and dangerous, experts explained.
For example, the 1918 Spanish flu pandemic, caused by the first emergence of the H1N1 flu strain, had a death rate greater than 2.5%, according to the CDC.
"Influenza doesn't have the same mortality rate right now as Covid-19," said Dr Aaron Glatt, an expert with the Infectious Diseases Society of America. "Both can be fatal. There's an awful lot more flu around, but thank God it's not as dangerous as Covid-19."
Older folks much more at risk
There's one important difference – Covid-19 appears to be most harmful to old people or those with underlying health problems that make them more susceptible to infection or pneumonia, Glatt added.
"No child has died of Covid-19," Glatt said. "There have been hundreds of cases and not one child under the age of 10 has died from Covid-19."
By comparison, 125 children in the United States have died from the flu this season, the CDC says.
One other important difference: The new coronavirus appears to be more infectious than the seasonal flu, experts said.
People carrying the new coronavirus appear to spread the infection, on average, to an additional 2.2 people, federal health officials said in a recent letter in the New England Journal of Medicine.
That's again on par with the pandemic 1918 Spanish flu, in which each infected person, on average, passed the virus on to between two and three people, said Dr Waleed Javaid, director of infection prevention and control at Mount Sinai Downtown in New York City.
A virus new to humans
That figure for the regular seasonal flu is around 1.3 new people infected for every person with the flu, according to a 2014 paper in BMC Infectious Diseases.
The 1957 (1.6), 1968 (1.8) and 2009 (1.5) influenza pandemics also had lower infection rates than the coronavirus, according to data from that paper.
People also shouldn't assume that the coronavirus will fade as winter turns to spring turns to summer, as happens with the seasonal flu, said Marc Lipsitch, a professor of epidemiology with the Harvard T.H. Chan School of Public Health.
"As a virus new to humans, [the coronavirus] will face less immunity and thus transmit more readily even outside of the winter season," Lipsitch added. "Changing seasons and school vacation may help, but are unlikely to stop transmission.
"Like pandemic flu, it might transmit widely outside of season," Lipsitch noted.
Transmission through mucous membranes
Both the new coronavirus and the flu spread in the same way, mainly through droplet transmission, Javaid said.
"If I sneeze or I cough, small respiratory particles fly into the air about three to six feet and fall to the ground," Javaid said. "Within those three to six feet, people can get exposed."
When those droplets land on a surface, they can be picked up by someone's hand touching that surface. If the person touches their eyes, nose or mouth, the virus can be transmitted thorough the mucous membranes, Javaid explained.
"We all touch our faces more than 20 times an hour. Every four or five minutes we are touching our face. I touched my face twice talking to you, already," Javaid said.
Carriers without symptoms
In another similarity, people carrying either virus can walk around without showing any active symptoms.
As many as three out of four people carrying the seasonal flu have no symptoms, according to a 2014 British study published in The Lancet.
People infected with either virus might be contagious before symptoms develop, making it difficult to control their spread, Javaid said.
When symptoms occur, Covid-19 virus appears to be more akin to the common cold than the flu. Coronavirus symptoms include fever, cough and shortness of breath, all of which may appear between two and 14 days after exposure, the CDC says.
The flu has those symptoms as well as sore throat, muscle aches, headaches and fatigue, the CDC says.
People with the flu have one important advantage, in that antiviral drugs like Tamiflu are available to reduce the length and severity of their illness, Glatt noted.
No similar antiviral is yet available to treat Covid-19 or the virus causing it. However, a coalition of European researchers found there are as many as 31 approved antiviral drugs that could potentially be effective against Covid-19.
No vaccination available
Repurposing these drugs as a Covid-19 therapy would have "a substantially higher probability of success to market as compared with developing new virus-specific drugs and vaccines, and a significantly reduced cost and timeline to clinical availability," the researchers wrote in the International Journal of Infectious Disease.
Glatt said he's not optimistic that an antiviral that's effective against the coronavirus will be found quickly.
"I doubt, although there's a lot of effort being put into it, that we're going to come up with an antiviral right away for the treatment of Covid-19," Glatt said. "Who knows, but I wouldn't count on that."
By the same token, there's a vaccine for the flu, but a vaccine for coronavirus won't be available for a year at the earliest, according to Dr Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases.
Given that, the best prevention for the coronavirus appears to be the same as for the common cold, experts said – wash your hands frequently, avoid contact with sick people, cover your cough or sneeze with your elbow to prevent hand contamination, and stay home if you're ill.
People who have chronic illnesses should make sure their disease is under control, to prevent their infection risk, Javaid said. For example, people who have diabetes should make sure their diabetes is under control.
Image credit: iStock