Flu vs. COVID: How to Tell Them Apart

COVID isn't the flu. Here's what you need to know and how testing can help you know what you're treating.

Diagnostics Testing|Sep. 27, 2021

COVID isn't the flu. And the flu isn't COVID. Here's what you need to know as we head into respiratory virus season — and how you can know it.

Flu vs. COVID-19: Telling Them Apart
These viruses can have the appearance of nearly being twins.

  • Fever or feeling feverish and having chills?
  • Cough?
  • Shortness of breath or difficulty breathing?
  • Fatigue?
  • Sore throat?
  • Runny or stuffy nose?
  • Muscle pain or body aches?
  • Headache?
  • Vomiting and diarrhea?
  • Even change in or loss of taste or smell?

All are symptoms that someone may have for both.

The Centers for Disease Control and Prevention (CDC) report "COVID-19 and flu can spread from person-to-person between people who are in close contact with one another (within about 6 feet). Both are spread mainly by large and small particles containing virus that are expelled when people with the illness (COVID-19 or flu) cough, sneeze, or talk."

With the COVID-19 pandemic continuing and flu season in the Northern Hemisphere set to begin with a peak around the new year — and as mitigating factors like distancing and wearing masks vary from state to state — there's one way to know for sure what you're dealing with, to put the ID in COVID … or the flu.

Testing.

A Terrible "Twindemic"
The Wall Street Journal reports "the coming flu season is on track to be worse than the last one, according to health experts, who fear an influx of cases could further strain hospitals already overwhelmed by the surge in the Delta variant of the coronavirus."

Why is it predicted to be worse this year? In part, say health experts, it stems from the good steps taken last year to socially distance and mask up. Those precautions led to a lighter year for the flu in 2020. But those have been largely abandoned in many places.

Worse, with fewer flu cases, this year's flu shot formulations are based on less data, meaning their effectiveness could be lessened.

"The 'twindemic' — a coinciding flu and COVID-19 epidemic — overwhelming our hospitals was thankfully avoided last year. But that does not mean it is no longer possible," Mark Roberts, director of the Public Health Dynamics Laboratory at Pitt Public Health, told Popular Science. "If anything, our models show that we should be more concerned this year about the possibility of a surge in COVID-19 hitting at the same time as a massive flu outbreak in areas of the country with low vaccination rates against both diseases."

Protect Yourself with Testing, Vaccines
Testing plus vaccines has always been our best bet to finally put an end to this pandemic and fully return to life.

Because "both flu viruses and the virus that causes COVID-19 can be spread to others by people before they begin showing symptoms; by people with very mild symptoms; and by people who never experience symptoms (asymptomatic people)," the CDC recommends the COVID vaccine plus a flu shot: "Flu vaccines and COVID-19 vaccines can be given at the same time."

And, because the flu, COVID-19, and other respiratory illnesses can present similarly, "testing is needed to tell what the illness is and to confirm a diagnosis," the CDC advises. "People can be infected with both flu and the virus that causes COVID-19 at the same time."

Testing can take place on your own or at your doctor's office.

BinaxNOW is the most widely used and studied rapid antigen test in the U.S. It provides results within 15 minutes and is authorized in three different ways. You can 1) buy it over the counter from your local retailer such as CVS Pharmacy, Walgreens and Walmart; 2) have it proctored at-home; or 3) get tested from your healthcare professional at a doctor's office or community testing site to determine if you have COVID-19.

You can also ask your healthcare provider for Alinity m Resp-4-Plex's simultaneous testing or your urgent care or pharmacy for an ID NOW rapid molecular test to screen for …

  • Influenza types A and B.
  • RSV, a common respiratory virus that typically causes mild, common-cold-type symptoms but can be severe for both young infants and older adults.
  • And, of course, COVID-19.

We remain ever vigilant monitoring COVID's viral strains and you can have confidence that our tests are designed to detect variants such as Delta, Mu, R.1 and more.

This story was originally published on September 27, 2021 and updated on June 15, 2022.

IMPORTANT SAFETY INFORMATION

EMERGENCY USE AUTHORIZATIONS

The BinaxNOW™ COVID-19 Antigen Self Test is a lateral flow immunoassay intended for the qualitative detection of nucleocapsid protein antigen from SARS-CoV-2 from individuals with or without symptoms or other epidemiological reasons to suspect COVID-19 infection when tested twice over three days with at least 36 hours between tests. This test is authorized for non-prescription home use with self-collected direct anterior nasal (nares) swab samples from individuals aged 15 years or older or adult collected anterior nasal swab samples from individuals aged two years or older.

The BinaxNOW COVID-19 Ag 2 Card is a lateral flow immunoassay intended for the qualitative detection of nucleocapsid protein antigen from SARS-CoV-2 in direct anterior nasal (nares) swab samples from COVID-19 symptomatic individuals tested twice over three days with at least 36 hours between tests within the first seven days of symptom onset.  

This test is authorized for use with direct anterior nasal (nares) swab samples from individuals without symptoms or other epidemiological reasons to suspect COVID-19, when tested twice over three days with at least 36 hours between tests. Testing is limited to laboratories certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. §263a, that meet the requirements to perform moderate, high, or waived complexity tests. This test is authorized for use at the Point of Care (POC), i.e., in patient care settings operating under a CLIA Certificate of Waiver, Certificate of Compliance, or Certificate of Accreditation.  

The BinaxNOW COVID-19 Ag Card 2 Home Test is a lateral flow immunoassay intended for the qualitative detection of nucleocapsid protein antigen from SARS-CoV-2 in direct anterior nasal (nares) swabs from individuals with or without symptoms or other epidemiological reasons to suspect COVID-19 infection when tested twice over three days with at least 36 hours between tests. This test is authorized for non-prescription home use with self-collected observed direct anterior nasal (nares) swab samples from individuals aged 15 years or older or adult collected anterior nasal swab samples from individuals aged two years or older. The BinaxNOW COVID-19 Ag Card 2 Home Test is to be performed only with the supervision of a telehealth proctor.  

The BinaxNOW™ COVID-19 tests have not been FDA cleared or approved. They have been authorized by the FDA under an emergency use authorization. They have been authorized only for the detection of proteins from SARS-CoV-2, not for any other viruses or pathogens, and are only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use of in vitro diagnostics for detection and/or diagnosis of COVID-19 under Section 564(b)(1) of the Federal Food, Drug and Cosmetic Act, 21 U.S.C. § 360bbb-3(b)(1), unless the declaration is terminated or authorization is revoked sooner.

For serial testing, the BinaxNOW COVID-19 Antigen Tests should be performed twice over 3 days, at least 24 hours (and no more than 48 hours) apart. For symptomatic use, a single test can be used.