The flu, a common cold and COVID-19 are contagious respiratory illnesses that have similar symptoms, so it can be difficult to tell the difference. They are caused by different viruses, and in general, testing is needed to help confirm a diagnosis.

Dr. Karan Shukla

“Both COVID-19 and the flu can spread before you know you have an illness, or symptoms,” said Dr. Karan Shukla, of Novant Health Randolph Family Medicine in Charlotte. “COVID-19, though, is much more contagious among certain populations and age groups versus the flu. COVID-19 has been shown to spread quickly and is more known to have super-spreader events compared to the flu.”

Influenza (flu)

“Getting the yearly flu vaccine is the best way to protect against flu,” Shukla said. “It can reduce the risk of flu illness, the rates of hospitalizations and flu-related deaths. You should generally get the flu vaccine before the flu virus starts circulating in your community. The CDC recommends that in early fall everyone starts to get vaccinated.”

Flu vaccinations are a strong preventative tool for people with chronic health conditions, Shukla said. It can help women who are expecting and their newborn babies from getting flu. Flu vaccines have been shown to prevent and reduce the severity the illness for people who get vaccinated, but still get sick. Getting vaccinated protects you, your family, neighbors and the people around you.

Influenza can cause mild to severe illness, and at times can lead to death. Flu is different from a cold. Flu usually comes on suddenly. People who have flu often feel some or all of these symptoms:

  • Fever or feeling feverish/chills.
  • Cough.
  • Sore throat.
  • Runny or stuffy nose.
  • Muscle or body aches.
  • Headaches.
  • Fatigue.
  • Vomiting and diarrhea, though this is more common in children than adults

How to get your flu vaccine

Current Novant Health patients: schedule your shot with your primary care provider here.

Don’t have a primary care provider? Visit one of our walk-in clinics.

Common cold

Symptoms of a cold usually peak within 2-3 days and can include:

  • Sneezing.
  • Stuffy nose.
  • Runny nose.
  • Sore throat.
  • Coughing.
  • Mucus dripping down your throat, also known as post-nasal drip.
  • Watery eyes.

Colds are usually milder than flu, according to the CDC. People with colds are more likely to have a runny or stuffy nose. Colds generally do not result in serious health problems, such as pneumonia, bacterial infections or hospitalizations. There is no vaccine for the common cold and it is not treatable with antibiotics because it is caused by a virus.


While the three illnesses share several symptoms, Shukla said there are a few key things that help set them apart. COVID-19 symptoms can range from mild to severe, and may appear 2-14 days after exposure to the virus.

Symptoms include:

  • Fever or chills.
  • Cough.
  • Shortness of breath or difficulty breathing.
  • Fatigue.
  • Muscle or body aches.
  • Headache.
  • New loss of taste or smell.
  • Sore throat.
  • Congestion or runny nose.
  • Nausea or vomiting.
  • Diarrhea.

Because the flu and COVID-19 are caused by different viruses, a flu vaccine will not protect against COVID-19. However, you can schedule a flu shot and a COVID-19 booster at the same time.

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