Every winter, families face the same worry when someone gets sick: Is this just a cold, the flu or another respiratory virus?
Now, with influenza (flu), COVID-19 and RSV (respiratory syncytial virus) circulating at once, it’s possible to catch more than one virus at the same time…or get them one right after another.
Getting two or more respiratory viruses at the same time is called a co-infection. While co-infections aren’t common, they can be more serious. Here’s how to spot them, when to test and how to keep you and your loved ones safe.
Understanding co-infections
A co-infection happens when your body is fighting more than one virus at once. For example, you could test positive for both flu and COVID-19 or a child could have RSV and the flu. In rare cases, people even get all three (a triple threat).
“All three viruses are spread through similar respiratory droplets and can exist in the same environment, making co-infection a possibility,” said Aneesh Narang, MD, an emergency medicine physician with Banner - University Medicine.
Each virus on its own can cause significant illness. Together, they may lead to more severe symptoms, longer recovery and complications.
“Those most at risk are older adults and people with chronic health problems like lung, kidney or heart disease, diabetes or a weakened immune system,” Dr. Narang said. “Younger children, especially infants, are also at high risk, especially those with congenital heart disease, chronic lung disease or born prematurely.”
If you are pregnant, you are also at higher risk due to immune system changes that occur during pregnancy.
What are the symptoms of each virus?
Because flu, COVID and RSV symptoms overlap, it’s not always possible to know what you have without testing.
Shared symptoms include:
- Fever and chills
- Cough
- Runny nose or congestion
- Fatigue or tiredness
- Sore throat
- Headache
Dr. Narang explained how symptoms can vary:
- Flu often starts suddenly, with muscle aches, chills and high fever. Children may also throw up (vomit) or have diarrhea.
- COVID can cause loss of taste or smell, severe sore throat (like swallowing razor blades) and sometimes digestive issues. Symptoms may come on gradually. Shortness of breath is more consistent with COVID, but it can also happen with the flu.
- RSV typically develops gradually. It often starts with congestion, runny nose and cough. Wheezing or difficulty breathing is common, especially in children and older adults.
How to test for flu, RSV and COVID
Testing is the only way to confirm which virus you have and it can guide treatment.
“Many hospitals have rapid antigen or PCR-based testing that can check for these viruses quickly,” Dr. Narang said. “These multiplex tests can be helpful in certain situations, especially if you are at higher risk or have severe symptoms. Knowing your results can also help you protect others who may be at high risk.”
There are also at-home tests available, though they may not always be as accurate as lab-based options.
Most healthy adults and children don’t routinely need testing, since results may not change treatment. But testing can be more important if:
- You’re at higher risk (if you're an older adult, an infant, pregnant or have a chronic condition)
- You need to know if you should isolate to protect yourself, your family, roommates or coworkers
- You’re caring for someone vulnerable
When to call a doctor
Most people can manage mild symptoms at home with rest, fluids and over-the-counter (OTC) medicine. But some warning signs mean it’s time to call your provider.
“If you’re high risk, such as being elderly, very young, pregnant, immunocompromised or have a chronic medical problem (like obesity, diabetes or heart problems), you should consider seeing your provider,” Dr. Narang said.
Contact your provider as well if:
- Your symptoms start to improve, but then return
- You show signs of dehydration
- You’re having a hard time managing symptoms
Antiviral medications can help treat both flu and COVID-19, but timing matters.
- For the flu, antivirals work best if started within the first 48 hours of symptoms.
- For COVID, oral antivirals are most effective when started as soon as possible, but they can still work if given within five days of symptom onset.
“Don’t delay seeking care if your illness is severe or if you have a high-risk condition,” Dr. Narang said.
Go to the ER if you or a family member has:
- Severe shortness of breath or wheezing
- Chest pain or pressure
- High fever that doesn’t improve (103°F or higher in adults; 102.2°F in children; 100.4°F or higher in a baby younger than 3 months)
- Severe dehydration (no urine, dizziness, dry mouth)
- New confusion or weakness
- Difficulty staying awake or waking up
- Bluish lips, hands or feet
- Severe vomiting or can’t keep fluids down
- Coughing up blood
Can I get vaccinated for all three?
Yes, you can, and you should. Vaccines remain the strongest tool to reduce your risk of serious illness from flu, COVID and RSV.
“It is generally considered safe to get all these shots during the same season or even at the same time,” Dr. Narang said. “Some people may have more side effects if they get shots at the same time, like arm pain, swelling, headache or tiredness, but these are usually mild and short-lived.”
The RSV vaccine is recommended for specific groups, including older adults, pregnant people and certain infants. Flu shots and COVID boosters are recommended for nearly everyone.
Schedule your flu shot today. Speak with a Banner Health specialist about RSV and COVID-19 boosters.
How to lower your family’s risk
Along with vaccines, everyday prevention goes a long way in reducing your risk of co-infections:
- Wash your hands often with soap and water
- Wear a mask in crowded indoor spaces during peak season
- Cover coughs and sneezes with your elbow or a tissue
- Clean high-touch surfaces, such as doorknobs and phones, regularly
- Stay home when you’re sick to protect others
The bottom line
Flu, COVID and RSV are here to stay. Though not common, it’s possible to get more than one virus at the same time. Testing can be helpful if you’re at high risk or severely ill, while vaccines and good hygiene practices can provide the best protection.
Take action today:
- Schedule your flu shot at a Banner Urgent Care or Banner Health Clinic near you
- Talk to your doctor about RSV and COVID boosters
- Know where to get tested if you or a loved one feels sick
