Making Sense of COVID-19, the Flu, and RSV 

Making Sense of COVID-19, the Flu, and RSV

This article is for people who are at risk for getting COVID-19, the flu, or respiratory syncytial virus (RSV); or anyone who's interested in learning more about these infections. The goal of this activity is to help people and their care partners talk to and work with their doctors about these respiratory viral infections.

You will learn about:

  • What a respiratory viral infection is

  • COVID-19, the flu, and RSV and symptoms of each

  • Who's at a higher risk of severe illness

  • How COVID-19, the flu, and RSV can spread and ways to help protect yourself and others

  • Taking to your doctor and questions you can ask

The information on COVID-19 is continually changing. The content in this activity is accurate based on the information that was available at the time of its publication. This resource is provided for educational and informational purposes only. We do not provide medical advice, diagnosis, or treatment.

Test Your Knowledge

What Is a Respiratory Viral Infection?

Respiratory viral infection is a general term used for an infection in your respiratory system -- your nose, sinuses, throat, airways, and lungs -- caused by a virus.

Viruses are extremely small organisms found everywhere on Earth. Viruses don't have everything they need to replicate, or make more viruses, on their own. They need to infect the cells of a host -- such as a human, animal, or plant -- in order to do so. Oftentimes, they severely damage or kill the host cells during infection.

Types of Respiratory Viral Infections

Many respiratory viral infections happen or start in your upper respiratory tract (your nose, sinuses, and throat), including the common cold which is caused by a group of viruses called rhinoviruses.

Other respiratory viral infections include:

  • COVID-19 that usually starts in your upper respiratory tract and is caused by a coronavirus

  • Influenza ("the flu") that infects your nose, throat, and lungs and is caused by several different influenza viruses

  • RSV that infects your nose, throat, sinuses, airways, and lungs

  • Pneumonia, a lung infection that may be caused by several different viruses

Bronchiolitis -- inflammation (swelling) of the small airways in the lungs -- and croup (inflammation of the upper and lower airways) can also happen, especially in children.

Respiratory Viral Infections Can Have a "Season"

Viruses exist year-round, but certain respiratory viral infections can have a "season" when they're most common in the United States. The exact reason why some viruses are more common during certain times of the year is not exactly known.

The seasons for different viruses and infections can also overlap or happen at the same time. So, it's important to know that getting 1 infection can sometimes make it easier for you to get other viruses and illnesses.

What to Know About COVID-19, the Flu, and RSV

Anyone at any age can get COVID-19, the flu, and RSV. You can also have them separately or at the same time, and you can even get infected and get sick with each virus more than once.


How Does It Spread?

When Are You Contagious?

How Sick Can You Get?


Mainly through the air when someone who's infected talks, coughs, or sneezes.

You're likely most infectious the first 5 days after you get symptoms and/or test positive, but you can also spread COVID-19 starting 2 days before symptoms or testing positive.

Most people will have mild or no symptoms. But COVID-19 can be severe and even deadly and lead to symptoms, severe illness, and complications (additional problems) that can be long lasting. It can be especially dangerous for elderly people and people who are pregnant, smoke, or have certain health conditions.


Can be spread before you know you're sick and up to 7 days after. Some people -- including children and those who have weakened immune systems -- can spread it even longer.

Some people may have mild symptoms, but the flu can be severe and even deadly. Complications can happen to anyone, but people who are 65 or older, younger than 5, pregnant, or have certain health conditions are at a higher risk.


Through the air and through direct contact (RSV can live on objects for hours).

Most likely to be spread during the first week after you're infected. Infants and people who have weakened immune systems can spread it for up to 4 weeks, even after symptoms stop.

Most will have mild, cold-like symptoms and recover on their own in 1 to 2 weeks. People at a higher risk for severe illness include those who have a heart or lung condition or a weakened immune system, older adults (especially 65 and older), babies born prematurely or 12 months old and younger, and children living with certain health conditions.

Is It COVID-19, the Flu, or RSV?

COVID-19, the flu, and RSV share some of the same symptoms, but they are caused by different viruses and can affect you differently.

Compared with the flu and RSV, with COVID-19 you may:

  • Lose your sense of taste or smell

  • Get symptoms 2 to 14 days after exposure

  • Have different complications

Talking to Your Doctor

Covering your mouth and nose when you cough, sneeze, or blow your nose; wearing a mask; washing your hands; and cleaning frequently touched objects can help prevent the spread of many respiratory viral infections. Getting tested and making sure you get any recommended vaccines are also important to help protect you and those around you.

If you have any symptoms or think you've been exposed to COVID-19, the flu, and/or RSV, contact your doctor, especially if you're at a higher risk for severe illness or around someone who is.

Dr Greg Poland talks about what you should know about the respiratory viral infections COVID-19, the flu, and RSV.

Questions to Ask Your Doctor and Healthcare Team

Questions you can ask about COVID-19, the flu, and RSV can include:

  • What should I do if I'm exposed, or think I've been exposed?

  • When should I contact you or get tested?

  • What symptoms should I look for?

  • Am I at a higher risk for severe illness or complications?

  • How can I protect myself and others?

  • Which vaccines do you recommend?

  • Where can I find more information and additional resources?

Test Your Knowledge

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You have successfully completed the program Making Sense of COVID-19, the Flu, and RSV.

View Additional Materials on this topic that you may find useful:

About COVID-19

Symptoms of COVID-19

Similarities and Differences Between Flu and COVID-19

Influenza (Flu)

About Flu

Key Facts About the Flu


RSV Symptoms

PDF Downloads

Patient Handout

Authors and Disclosures


Gregory A. Poland, MD, FIDSA, MACP, FRCP(London)

Professor of Medicine and Infectious DiseasesMayo Clinic College of MedicineDirector of the Vaccine Research GroupMayo ClinicRochester, Minnesota

Gregory A. Poland, MD, FIDSA, MACP, FRCP(London), has the following relevant financial relationships:Consultant or advisor for: 3D Communications; AiZtech; AstraZeneca UK Limited; Emergent Biosolutions; Exelixis, Inc.; Genevant Sciences, Inc.; GlaxoSmithKline; Janssen Global Services, LLC; Lilly; Medicago USA; Merck & Co., Inc.; Moderna; Regeneron Pharmaceuticals, Inc.; Syneos Health; Valneva; Vyriad.Royalties from: ICW, Inc.Patent beneficiary of: ICW, Inc.

Clinician Reviewer

Karen Badal, MD, MPH

Senior Medical Education Director, Medscape, LLC.

Karen Badal, MD, MPH, has no relevant financial relationships.


Anita A. Galdieri, PharmD, RPh

Associate Director, Content Development, Medscape, LLC.

Anita A. Galdieri, PharmD, RPh, has no relevant financial relationships.


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