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

Viruses spread more easily in winter, partly because we spend more time indoors. Winter is also the time during which we see an increase in cases of the common cold, flu, and Respiratory Syncytial Virus (RSV). In the last few years, COVID-19, which is still present in our communities, has been added to that list.

With so many viruses lingering in the air, knowing the difference between these conditions is essential. Here are some answers to common questions. We hope this will help you understand when to test or to seek medical help:

  • With the symptoms for the flu, RSV, and COVID-19 being so similar, how can I tell these viruses apart?

Testing is the key to identifying which virus could cause the concerning symptoms. Testing is also very important for treatment options, as the different viruses have very different treatments. 

It is often impossible to tell them apart until testing is completed,” Dr. Kenneth L. Woods, DO, MPH, Medical Director, Infectious Disease, Trinity Health System, said. 

In some cases, younger children and adults may have one or more conditions at the same time. For instance, they could have flu and RSV or flu and COVID-19. Early testing for babies and adults who are 75 or older is essential because their immune systems aren’t as strong or as fully developed yet. 

“Early testing should be done especially with severe disease, elderly, or people with chronic medical problems as those are the ones who tend to do worse with a viral infection and may be eligible for specific treatments,” Dr. Woods said.

There are also therapies available for RSV, but the supply is limited at this time. Patients 12 and older with COVID-19 and at risk for severe disease can take Paxlovid within the first five days of the onset of symptoms. 

“If one virus is going through a household, and other household contacts share similar symptoms, it is most likely the same virus and points us in a direction while awaiting test results,” Dr. Woods said.  

“Just a reminder,” he added, “antibiotics do not treat any of these viral infections, but antiviral medications may be available depending on the specific virus and scenario.”

  • Which should I be most concerned about: flu, RSV, or COVID-19?

“All three of these viruses can cause serious illness or respiratory failure,” Dr. Woods said. “More important than which virus is the severity of the illness or chronic medical conditions, like chronic heart/lung diseases, asthma, COPD, obesity, immunosuppression or diabetes, that would make someone higher risk for severe disease.”

This is particularly true for babies under age one and older adults with asthma, heart failure, or COPD. 

“Our concern should mostly be on the flu since there is a poorer prognosis especially in children with comorbid conditions such as asthma and other respiratory conditions,” Dr. Thach Nguyen, Pediatrician, Trinity Health System, said.

Contact your primary care provider or seek medical help immediately if you or a loved one fall into any of these groups and have symptoms of flu, RSV, or COVID-19. 

  • When should I go to the doctor or the emergency room?

If you or a loved one is having difficulty breathing–a common symptom of severe flu, RSV, and COVID-19 infections–you should immediately head to an urgent care center or the ER. Other symptoms to watch out for include gasping for air, low pulse-oximetry level (< 90 percent), shallow or rapid breathing, chest pains, lightheadedness, new onset confusion, passing out or the feeling of passing out, and an inability to drink or swallow. 

“If a patient is experiencing increased work of breathing, persistent vomiting, or is not drinking well and has signs of dehydration, they should seek care with their provider or ER,” Dr. Nguyen said. “Feeling tired for no reason or being unable to breathe is something to worry about, regardless of the infection.”

If a child with RSV has a high fever, experiences vomiting, or has difficulty eating or drinking, you should seek urgent help, Dr. Nguyen added. In flu cases, chest pain, persistent vomiting, or sudden dizziness are serious signs and need immediate medical attention. 

If you or someone with COVID-19 are confused, disoriented, or have discolored lips or hands, it’s time to head to the ER. You can schedule a virtual or in-office visit if the symptoms are milder, like those of the common cold.

“The earlier treatment can be started, the better the success is to be expected,” Dr. Woods said. “Oftentimes delays in seeking care result in fewer treatment options.”

  • Do older adults need a different type of flu vaccine for better protection?

The simple answer is: Yes.

“Those 65 years or older are recommended to get a ‘high dose’ flu vaccine if it is available, compared to people under 65 years old,” Dr. Woods said. “If unavailable, they should obtain routine annual flu vaccination.”

The CDC made this recommendation for the 2022-2023 flu season after reviewing studies that suggest they’re more effective for people in this age group. That extra protection is crucial for older adults whose immune systems don’t respond as strongly to vaccines as younger populations. 

Adults 65 and older also have an increased risk of complications and hospitalization. For this demographic, any of the following high-dose vaccines are recommended:

Fluzone High-Dose Quadrivalent vaccine

Flublok Quadrivalent recombinant  flu vaccine

Fluad Quadrivalent adjuvanted flu vaccine 

  • Do children need a different type of flu vaccine for better protection?

The simple answer is: No, but with a caveat. 

“Per guidelines in terms of the flu shot, there is no preference in terms of what flu shot to get, just as long as they are quadrivalent,” Dr. Nguyen said. 

All patients over six months of age are recommended for both the annual influenza vaccine and COVID-19 vaccines, Dr. Woods said. “If a child is six months to eight years old and has received two doses of flu vaccine in prior season(s), then they only need one current season booster. The child that does not have prior two doses, is the ONLY one who should receive two doses at least four weeks apart.” 

The CDC recommendation for this can be found here.  

Dr. Nguyen advises entire families to get the flu shot for maximum protection. 

If you haven’t gotten your annual flu vaccine, now is the time. Talk to your healthcare provider if you are allergic to eggs or any vaccine ingredients other than eggs or for any other concerns. You can find information about vaccine ingredients in the package inserts.

“Prevention for flu and COVID-19 is very similar,” Dr. Woods said. “Vaccines are the most helpful step in preventing disease with both of these.”

  • What else can I do to protect myself and my family?

Dr. Woods and Dr. Nguyen gave several suggestions for protection: 

  1. Avoiding crowded areas during times of high virus activity in the community, especially in poorly ventilated indoor areas. 
  2. When ill, staying home is very important to prevent person-to-person spread of these viruses. 
  3. If you have to go around others while ill, wearing a mask can help reduce your risk of spreading a viral infection to others.
  4. Hand washing with soap and water or an alcohol-based hand sanitizer is also paramount to prevention spread of these and other infections. 
  5. Furthermore, taking good control of your overall health and other medical conditions is beneficial to keep a healthy immune system and lower severity of illnesses with virus infections.

“In cases of RSV, keep infants younger than 12 months away from people coughing or sneezing or ask them to wear a mask,” Dr. Nguyen said. 

The takeaway. While there are treatment options for RSV, the flu, and COVID-19, not every age group qualifies for them. And in some cases, the medications may be in short supply. The best way to protect yourself and your loved ones is by getting the flu and COVID-19 vaccines. Keep the little ones home when sick, and wear masks indoors as the CDC recommends. 


GRADE: Higher Dose and Adjuvanted Influenza Vaccines for Adults Aged ≥65 Years | CDC

Quadrivalent Influenza Vaccine | CDC

Who Should and Who Should NOT Get a Flu Vaccine | CDC