Since COVID-19 began spreading, the public has often tried to compare it with the flu. Finding similarities in something we are trained to recognize can be reassuring when you’re fighting an invisible enemy.
But how alike are COVID-19 and the flu, really? We took a closer look, comparing and contrasting the two diseases with information available through the Centers for Disease Control and Prevention. Here’s what we know.
Similarities: Symptoms range from mild to severe. Common symptoms include fever, cough, fatigue, body aches and headaches.
Differences: Flu symptoms appear more quickly, usually within one to four days. COVID-19 symptoms may not appear for two to 14 days after exposure to the virus. Flu also presents with a wider variety of symptoms. You may also have a sore throat, a runny or stuffy nose, and vomiting and diarrhea (although this is more common with children). COVID-19’s unique symptom is shortness of breath, and the cough associated with it is dry.
It is important to note that new symptoms are arising, and not all symptoms are always present, according to the Ohio Department of Health. If you feel sick, stay home and call your doctor.
Similarities: Everyone is susceptible to either virus, but older adults and those with other health conditions are at a higher risk of developing severe symptoms.
Differences: Pregnant women and children under 5 are also considered high risk for the flu. These groups have not officially been added to the high-risk group for COVID-19.
Similarities: Transmission of COVID-19 and the flu seems to be almost identical. Both diseases are spread easily from person to person through small respiratory droplets containing the virus. These droplets appear when someone coughs, sneezes or even talks. Another common way to contract the virus is by touching surfaces where these droplets land and then touching your eyes, nose or mouth.
You can spread both viruses to others without being aware you are infected. It’s important to follow recommendations to stop the spread, like hand-washing and maintaining a 6-foot distance from others.
Differences: Flu tends to spread faster than COVID-19 because it has a shorter incubation period (time from infection to symptoms) and serial interval (time between cases) than COVID-19. Flu also appears to spread more easily before symptoms appear. People with COVID-19 can shed the virus 24–48 hours before symptoms appear, but it doesn’t seem to be a major driver of infection.
Despite this, current data suggests one person with COVID-19 infects 2–2.5 people on average, compared to someone with the flu who will infect an average of 1.3 people. Children are more likely to spread the flu than adults, but early data from household transmission studies in China indicates the opposite is true for COVID-19.
Similarities: The actions we take to prevent the flu work against COVID-19 as well. These include frequent hand-washing, social distancing, disinfecting surfaces, and covering coughs and sneezes with a tissue or sleeve.
Differences: A new flu vaccine comes out each year to help prevent infection. There is no vaccine for COVID-19, but clinical trials are underway.
Similarities: We can test for the flu and COVID-19 to confirm infections. If you have recently traveled to an area with known COVID-19 cases or have been exposed to a person diagnosed with COVID-19, the CDC recommends you call your primary care doctor, and they will determine whether you need to be tested. People with other health conditions should call their doctor immediately, even if symptoms are mild. If you don’t have a primary care doctor, contact the Ohio Department of Health call center. The call center is open seven days a week from 9 a.m. to 8 p.m., and can be reached at 1 (833) 4-ASK-ODH (427.5634).
Differences: Right now, testing resources for COVID-19 are limited in the United States. While most people with symptoms can be tested for the flu, we won’t be able to test the same number of people for COVID-19. The CDC has offered guidelines for testing that recommend who should be tested, but decisions are being left to state and local health departments, and care providers.
Similarities: Some over-the-counter medications can be used to manage symptoms of both the flu and COVID-19, such as acetaminophen for fever reduction. Antibiotics should not be used to prevent or treat the flu, COVID-19 and all other viruses. Antibiotics only work on bacterial infections.
Differences: There are antiviral medications that can shorten the duration of the flu, ease symptoms and prevent complications. While several clinical trials are ongoing to develop medication to treat COVID-19, no approved treatments exist at this time.
Infection and mortality rates
Similarities: While the majority of flu and COVID-19 cases are mild, some do result in death.
Differences: As of March 24, 2020, the CDC reports that 44,183 people in the United States and United States’ territories tested positive for COVID-19 with a national mortality 544. This brings the total mortality rate to 1.2%.
Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, says the flu’s mortality rate is 0.1%. This would make COVID-19 more than ten times more lethal than the flu.
It’s important to note, though, that data is changing every day, and many mild cases of COVID-19 are not being confirmed through testing and counted. If all possible cases were confirmed, it would likely change the mortality rate.