COVID-19, RSV, and the Flu Could Be a Triple Threat This Fall

An illustration of red and orange painted COVID virus particles on a yellow-gold background.

Pabitra Kaity / Pixabay

Key Takeaways

  • COVID-19 is not the only respiratory illness that public health officials are concerned about this fall. Influenza (the flu) and respiratory syncytial virus (RSV) also pose risks.
  • People can get more than one of these respiratory illnesses at the same time.
  • All three viruses can cause similar symptoms; however, they are not treated the same way.

Although vaccination efforts continue throughout the United States—and some people are even able to receive booster shots—COVID-19 remains a concern.

But this fall, public health experts are also thinking about two other respiratory illnesses that will be circulating: influenza (or the flu) and respiratory syncytial virus (RSV).

Here's what you need to know about each illness and what you can do to protect yourself and your loved ones from getting sick as the weather cools.

The Viruses

COVID-19, the flu, and RSV are all highly contagious respiratory infections that are caused by viruses, each of which has different strains, variants, and subtypes.

  • COVID-19 is caused by the SARS-CoV-2 virus and its variants, which are still emerging.
  • As its name suggests, RSV is caused by a respiratory syncytial virus (the strains of which are classified into two groups: type A and type B).
  • In humans, the flu can be caused by several strains of influenza viruses, type A, B, and C—one or more of which can take precedence in a given flu season. Influenza A and its subtypes cause most outbreaks of the flu in people.

In the U.S., flu season typically starts by the end of October. While RSV is also typically a fall and winter virus, this year it started spreading in the U.S. over the summer. COVID-19 has been around all year since the pandemic started, but it might eventually take on a seasonal pattern.


COVID-19, the flu, and RSV share some common symptoms, including:

  • COVID-19, RSV, and the flu can all cause fever and coughing.
  • COVID-19 and the flu can cause fatigue, headache, congestion, sore throat, and body aches.
  • Some people with COVID-19 or the flu also experience gastrointestinal symptoms like nausea, vomiting, and diarrhea.

Virus-Specific Symptoms 

While the three illnesses do share some symptoms, there are also signs and symptoms that are specific to one or another.

For example, loss of taste and smell is a hallmark symptom of COVID-19. RSV is more likely to produce wheezing than COVID-19 or the flu.


All three respiratory illnesses carry the potential for serious symptoms and complications, and some people are more at risk for severe illness than others.

“Because symptoms can be similar, but treatments are not the same, it’s important for public health to educate the public and provide accurate information,” Sri Banerjee, MD, MPH, PhD, an epidemiologist at Walden University in Maryland, tells Verywell.


Severe COVID-19 illness can lead to hospitalization, the need for ventilation and intensive care treatment, and can ultimately be fatal.

For people who survive even mild infections, persistent symptoms, known as long COVID-19, is another complication to consider.


The flu can also have complications, including pneumonia and sepsis.

Risk is especially high for:

  • Infants
  • Children
  • Older adults
  • People with certain medical conditions
  • People who are pregnant
  • People with weakened immune systems

The flu can also be fatal. According to the Centers for Disease Control and Prevention (CDC), 12,000 to 61,000 people have died from the flu each year since 2010.


Gregory Poland, MD, the head of the Vaccine Research Group at the Mayo Clinic, tells Verywell that although RSV is best known as a virus in small children, anyone can catch it, and it can be dangerous for very young children and older adults.

RSV affects the lungs and its bronchioles (which carry air to the lungs). For most adults and kids, a case of RSV consists of mild cold-like symptoms, but a severe RSV infection can cause pneumonia and bronchiolitis. These complications most often occur in infants, people over 65, and people with lung, heart, or weakened immune conditions.

If you're sick with any respiratory illness and you are not getting better or your symptoms start to get worse, call your doctor or make a telehealth appointment. And if you have trouble breathing or develop a high fever, go to an urgent care center or the emergency room.

Banerjee says that in addition to being at risk of severe illness, you may have "contracted more than one virus which can weaken your immune system more than being sick with just one."


Symptoms of the three respiratory illnesses are common enough that "a physical exam can’t necessarily distinguish them," Banerjee adds. That means that your doctor may test you for the viruses.

There are separate tests for COVID-19, the flu, and RSV, but some companies have also created a single test for all three. Several of these combination tests have been granted emergency use authorizations (EUA) from the Food and Drug Administration (FDA).

Amesh Adalja, MD, MPH, senior scholar for the Center for Health Security at the Johns Hopkins School of Public Health and the lead researcher on a report published last year about home virus diagnostic tests on a single platform, tells Verywell that a “one swab, three tests” combination test would help providers diagnose the illnesses and choose the right treatment.

The report concluded that having rapid diagnostic testing tools that can be done at home would "greatly facilitate the safe conduct of many activities and heighten confidence that life will return to some semblance of normalcy."

David Persing, MD, the chief medical officer for Cepheid—a company with an EUA for a combination test, tells Verywell that the combination tests are mostly used for patients in the hospital, but that “if you go to an emergency room they may use the combination test, and some urgent care centers have them as well.” 

If you have respiratory symptoms, start with an at-home COVID-19 test, Adalja says. If an at-home test is negative but you still feel sick, Adalja says the next step is to get "a more sensitive PCR test" which can often detect COVID-19 "even if the home test cannot."

Make sure to tell your doctor your test results, especially if you're still having symptoms. While each illness has different protocols, it's usually better to start treatment sooner rather than later.


The medical treatments that are available for the flu and COVID-19 need to be started as soon as possible after you begin feeling sick.

If you are severely ill with any of the three infections, more intensive medical treatment might be needed.

COVID-19 Treatment

If you have COVID-19, certain things that you'd do for any other respiratory infection—such as resting and getting plenty of fluids—also apply. However, there are some treatments for COVID-19 that are not used with the flu or RSV.

One example is monoclonal antibodies, which are laboratory-made and mimic the antibodies that our bodies make during infections. The drugs are given by IV and require a doctor’s prescription.

Monoclonal antibodies interfere with the virus's ability to attach to and enter human cells. The antibodies can reduce the amount of the virus in the body and may help prevent severe illness, hospitalization, and death. But they must be given within a few days of the start of symptoms.

The FDA has also authorized the use of monoclonal antibodies to help prevent COVID-19 in some people with medical risk factors who are exposed to the virus.

Flu Treatment

In addition to resting and staying hydrated, flu symptoms can be treated with certain antiviral medications. These drugs work best when they are started within 48 hours of when you first feel sick, but they might be beneficial later on in some cases.

Since it's important to start treatment as soon as possible, your doctor might have you start taking an antiviral before the results of your flu test come back.

There are four FDA-approved antiviral drugs that are recommended for the 2021-2022 flu season: 

  • Oseltamivir phosphate (Tamiflu; also available as a generic)
  • Zanamivir (Relenza)
  • Peramivir (Rapivab)
  • Baloxavir marboxil (Xofluza)

The antiviral flu treatment that is right for you will depend on several factors, such as:

  • Your age
  • How long you've had symptoms and their severity
  • Whether you are taking other medications
  • Any medical conditions that you have (including whether you are pregnant or breastfeeding)

The length of treatment and possible side effects of each antiviral vary. Your doctor will discuss the risk and benefits with you, and your pharmacist can also answer any questions you have about the medication that you are prescribed.

If your child has the flu, they might also be able to take certain antivirals. Tamiflu and its generics can be given to infants as young as 14 days old.

RSV Treatment

If you have RSV, treatment will depend on how sick you are. If you have a mild case, you'll get better on your own in a week or two. Your doctor will likely recommend that you take a fever-reducing medication and get plenty of rest and fluids.

For a severe case of RSV, you might need to be hospitalized for a few days to receive intravenous (IV) hydration, oxygen therapy, and possibly mechanical ventilation to help you breathe.

What This Means For You

This winter, it's likely that three respiratory illnesses—flu, COVID-19, and RSV, will be circulating at the same time. Many of the steps that you can take to protect yourself from COVID-19, such as wearing a mask and social distancing, can also help you avoid the flu and RSV. Additionally, you can get vaccinated against COVID-19 and the flu.


As the old saying goes, an ounce of prevention is worth a pound of cure. Banerjee says that "personal prevention can be highly effective" at helping you avoid all three illnesses this winter.

Most of the steps that you can take to protect yourself and your loved ones are things that you are probably already familiar with because of COVID-19, such as:

  • Wearing a face mask
  • Washing your hands frequently with soap and water
  • Covering your cough
  • Social distancing
  • Avoiding contact with people who are sick


One of the best ways to protect yourself is to get vaccinated. You can get immunized against the flu and COVID-19, and both vaccines are effective at preventing severe illness, hospitalization, and death.

According to the CDCD, it's safe to get your flu shot and a COVID-19 shot (or booster) at the same time.

COVID-19 vaccines are paid for by the federal government which means that they're free. The flu vaccine is usually free at your doctor’s office and local pharmacy if you have health insurance. If you are uninsured, many community health clinics provide free flu shots.

Currently, there is no RSV vaccine. However, the FDA is currently reviewing an application for an RSV vaccine created by Moderna.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page. 

15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention (CDC). COVID-19: Transmission.

  2. Muñoz-Escalant JC, Comas-García A, Bernal-Silva S, et al. Respiratory syncytial virus B sequence analysis reveals a novel early genotype. Scientific Reports. 2021;11(1):1-11. doi:10.1038/s41598-021-83079-2

  3. Centers for Disease Control and Prevention (CDC). Types of Influenza Viruses.

  4. Centers for Disease Control and Prevention (CDC). Symptoms of RSV.

  5. Centers for Disease Control and Prevention. Flu Symptoms & Diagnosis.

  6. Centers for Disease Control and Prevention (CDC). Symptoms of COVID-19.

  7. Centers for Disease Control and Prevention (CDC). People With Certain Medical Conditions.

  8. Centers for Disease Control and Prevention (CDC). Post-COVID Conditions.

  9. Centers for Disease Control and Prevention (CDC). Disease Burden of Influenza.

  10. Centers for Disease Control and Prevention (CDC). RSV in Infants and Young Children.

  11. Food and Drug Administration (FDA). FDA authorizes REGEN-COV monoclonal antibody therapy for post-exposure prophylaxis (prevention) for COVID-19.

  12. Centers for Disease Control and Prevention. What You Should Know About Flu Antiviral Drugs.

  13. Fry AM, Goswami D, Nahar K, et al. Efficacy of oseltamivir treatment started within 5 days of symptom onset to reduce influenza illness duration and virus shedding in an urban setting in Bangladesh: a randomised placebo-controlled trialLancet Infect Dis. 2014;14(2):109-118. doi:10.1016/S1473-3099(13)70267-6

  14. Centers for Disease Control and Prevention (CDC). Prevent Getting Sick.

  15. Centers for Disease Control and Prevention (CDC). Interim Clinical Considerations for Use of COVID-19 Vaccines Currently Approved or Authorized in the United States.

Additional Reading

By Fran Kritz
Fran Kritz is a freelance healthcare reporter with a focus on consumer health and health policy. She is a former staff writer for Forbes Magazine and U.S. News and World Report.