Published: March 9, 2020 at 12:14 p.m. ET

By Quentin Fottrell

“While both the flu and COVID-19 (corona virus) may be transmitted in similar ways, there is also a possible difference: COVID-19 might be spread through the airborne route, meaning that tiny droplets remaining in the air could cause disease in others even after the ill person is no longer near,” Lisa Maragakis, senior director of infection prevention at Johns Hopkins Medicine in Baltimore, Md., wrote.

Of course, there are similarities between influenza and COVID-19, the disease caused by the new coronavirus. Both viruses are not treatable with antibiotics, and they have almost identical symptoms — fever, coughing, night sweats, aching bones, tiredness and, in the more severe cases of both viruses, nausea and even diarrhea. They can be spread by touch, coughing and sneezing.

Fatality rates also vary dramatically, depending on the individuals. No deaths occurred in those aged 9 years and younger, but cases in those aged 70 to 79 years had an 8% fatality rate and those aged 80 years and older had a fatality rate of 14.8%. The rate was 49% among critical cases, and elevated among those with preexisting conditions to between 5.6% and 10.3%, depending on the condition.

Other differences between coronavirus and influenza lie in what we don’t know. Adults with the flu, which has an average incubation period of 2 days, can infect others 24 hours before symptoms develop and up to 5 to 7 days after becoming sick. The incubation period for coronavirus is estimated at between 2 and 14 days, but little is currently known about its period of contagiousness.

Coronavirus appears to be transmitted with ease to about 2.3 people by each person infected in the community and those who are asymptomatic, said Antigone Barton, editor of ScienceSpeaks. “Because there’s no proven therapy or vaccine, as coronavirus spreads, it threatens to put a much greater burden on health systems than flu does, and greater than most or many are prepared for.”

How COVID-19 is transmitted