Flu vs. COVID-19: What are the differences?


As the worldwide outbreak of COVID-19 continues to develop, media outlets are sharing information on the ever-changing and unpredictable pandemic.

Recently, comparisons between influenza and COVID-19 have been drawn. While there are similarities, such as both being infectious viruses that can cause respiratory illness, differences exist between them as well.

According to Johns Hopkins Medicine, COVID-19 is caused by one virus, the novel 2019 coronavirus named SARS-CoV-2, while the flu is caused by several different types and strains of influenza viruses.

As a general overview, symptoms of COVID-19 include fever, cough and shortness of breath according to the Centers for Disease Control and Prevention.

On the other hand, the CDC shared that symptoms of influenza include fever, cough, sore throat, muscle aches, headaches, runny or stuffy nose, fatigue and occasionally vomiting and diarrhea.

In a Q&A, the World Health Organization distinguished the speed of transmission to be an important difference between the two viruses. The WHO stated that the median incubation periods and serial intervals of the two viruses differ.

“Influenza has a shorter median incubation period (the time from infection to appearance of symptoms) and a shorter serial interval (the time between successive cases) than COVID-19 virus,” reported the WHO. “The serial interval for COVID-19 virus is estimated to be five to six days, while for influenza virus, the serial interval is three days.”

While the methods of transmission are the same, from contact, droplets and fomites, there is a new possibility that COVID-19 is spreading through the airborne route.

“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,” according to Johns Hopkins Medicine.

While children are important factors of flu transmission within communities, data suggests that children are less affected than adults are, according to the WHO.

“For the COVID-19 virus, initial data indicates that children are less affected than adults and that clinical attack rates in the zero to 19 age group are low. Further preliminary data from household transmission studies in China suggest that children are infected from adults, rather than vice versa,” reported the WHO.

Additionally, the WHO stated that the mortality rate for COVID-19 appears to be higher than that of the flu.

“Mortality for COVID-19 appears higher than for influenza, especially seasonal influenza. While the true mortality of COVID-19 will take some time to fully understand, the data we have so far indicate that the crude mortality ratio is between three to four percent,” reported the WHO.

The available medical interventions are one major difference. There are no licensed vaccines or therapeutics for COVID-19, though the WHO states that there are over 20 vaccines currently in development. The flu, however, has antiviral drugs and vaccines developed to combat it.

The CDC urges all individuals to follow precaution and practice social distancing. Those showing symptoms should seek medical care.