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September 21, 2020: Overview of Similarities and Differences between Flu and COVID-19

With flu season approaching, recognizing the differences between seasonal flu and COVID-19 is important to ensure proper treatment.  

Influenza (Flu) and COVID-19 are both contagious respiratory illnesses, but they are caused by different viruses.  COVID-19 is caused by infection with a new coronavirus (called SARS-CoV-2) and flu is caused by infection with influenza viruses.  Because some of the symptoms of seasonal flu and COVID-19 are similar, it may be hard to tell the difference between them based on symptoms alone.  Testing may be needed to help confirm a diagnosis.

While more is learned every day, there is still a lot that is unknown about COVID-19 and the virus that causes it.  This topic compares COVID-19 and flu, given the best available information to date.

Signs and Symptoms


Both COVID-19 and flu can have varying degrees of signs and symptoms, ranging from no symptoms (asymptomatic) to severe symptoms.  Common symptoms that COVID-19 and flu share include:
• Fever or feeling feverish/chills
• Cough
• Shortness of breath or difficulty breathing
• Fatigue (tiredness)
• Sore throat
• Runny or stuffy nose
• Muscle pain or body aches
• Headache
• Some people may have vomiting and diarrhea, though this is more common in children than adults


Flu viruses can cause mild to severe illness, including common signs and symptoms listed above.

Other signs and symptoms of COVID-19, different from flu, may include change in or loss of taste or smell.

Approved Treatments

People at high-risk of complications or who have been hospitalized for COVID-19 or flu should receive supportive medical care to help relieve symptoms and complications.


Prescription influenza antiviral drugs are FDA-approved to treat flu.

While antiviral agents are being explored as a treatment for COVID-19 there are currently no drugs or other therapeutics approved by the Food and Drug Administration (FDA) to prevent or treat COVID-19.  Studies are in progress to learn more.


Vaccines for COVID-19 and flu must be approved or authorized for emergency use (EUA) by the FDA.


There are multiple FDA-licensed influenza vaccines produced annually to protect against the 3 or 4 flu viruses that scientists anticipate will circulate each year.

Currently there is no vaccine to prevent COVID-19.  Vaccine developers and other researchers and manufacturers are expediting the development of a vaccine to prevent COVID-19.

The key to becoming infected by either virus is taking precautions to prevent exposure!

(Source: Adapted from CDC)