COVID-19 + The Flu: Knowing the Differences and How to Prepare

As we move into the flu season during the COVID-19 crisis, a few questions arise for many:

  • How will the flu affect navigation of this global pandemic?
  • How will I be able to tell the difference between the two illnesses?
  • How can I best protect myself and my family?

While early 2020 numbers of Influenza (the flu) cases actually decreased, due to protective measures incorporated for COVID-19, as we head into the typical flu season, it is helpful to be familiar with the similarities and differences between the two illnesses, treatment options, and available testing to differentiate between the two.

Similar, Yet Different

Many leading health organizations, including the World Health Organization (WHO), agree that while there are many similarities between COVID-19 and the flu, there are also key differences in symptoms, duration of illness, and, most importantly, treatment. Knowing those differences can help each of us make the best decisions for our own and our family’s health in this season. 

Both the flu and COVID-19 are contagious, being passed from one person to another via touch, droplets (e.g. sneezes and coughs), and contaminated surfaces. Both can cause a range of symptoms from asymptomatic to severe illness, affecting primarily the lungs. 

Symptoms can include:

  • Cough
  • Sore throat
  • Shortness of breath
  • Runny nose
  • Feeling tired
  • Fever
  • Muscle aches
  • Headaches

Individuals sick with either illness may exhibit symptoms within one to four days after infection. However, some individuals infected with the coronavirus (SARS-CoV-2) may not exhibit symptoms until two weeks after exposure.

While physicians have been familiar with the symptoms and treatment of the flu for many years, our understanding of COVID-19 is still developing and we are starting to understand some of the key differences between these two diseases. The flu is caused by an infection with Influenza viruses, such as Influenza A and B, while COVID-19 is caused by an infection with SARS-CoV-2, 

According to the Centers for Disease Control and Prevention, COVID-19 seems to be more highly contagious. In addition, it has a longer period of time in which infected individuals can transmit the illness; this is typically around 7 days for the flu (including one to five days prior to symptoms) and at least 10 days after testing positive for COVID-19 (including one to two days prior to symptoms). Thus, individuals infected with either virus can transmit the disease prior to or even without having symptoms. 

Symptoms can also be more severe in individuals with COVID-19. For example, COVID-19 may cause loss in taste or smell, which is not typically seen with the flu. Furthermore, most people who are infected with the flu will recover in less than two weeks, while individuals with COVID-19 may have symptoms that persist for several weeks or even longer. 

Reducing Your Risk

The flu vaccine can reduce the risk for the flu, as well as severity and duration of symptoms if someone becomes infected. It is strongly recommended by the WHO to prevent flu infection. 

The flu vaccine does not affect a person’s risk for getting COVID-19, and guidance is available regarding optimal utilization of the vaccine in individuals with COVID-19. While an annual vaccine is available to protect against the flu, there is currently no commercially available vaccine available for COVID-19.

Staying consistent and thoughtful in protective actions can make a significant difference in lowering an individual’s risk for getting COVID-19. Simple risk reducing measures include frequent hand washing, wearing a mask when in public, covering coughs and sneezes, and disinfecting commonly used items and touch points. In addition, limiting contact with individuals outside of your own household, including via social distancing and avoiding large gatherings, reduces risk for exposure as well.

If You Get Sick

Common, at-home remedies for the flu include extra rest and staying hydrated. FDA-approved antiviral medications are available for those with the flu, and may be recommended to help address symptoms and potentially shorten the time an individual is sick. 

Possible treatment and vaccine options, including antiviral drugs, are being studied for COVID-19. 

Confirmation Through Testing

Because the symptoms of COVID-19 and the flu are similar, and may spread through a community at the same time, it can be challenging to know which illness an individual might have. Note, it is possible to be infected with both the flu and COVID-19 at the same time. To help confirm a diagnosis and guide appropriate treatment, testing is needed. 

The National Institutes of Health recommends testing for both COVID-19 and the flu for any individuals hospitalized due to symptoms associated with either illness, as well as in individuals suspected to be infected in communities known to harbor both sets of viruses.

COVID-19 & Flu Testing With Baylor Genetics

Testing for both SARS-CoV2 and Influenza A/B is available through select sites, including Baylor Genetics. In November 2020, BG became one of the first clinical diagnostic reference laboratories in the United States to launch a combined test for COVID-19 and the flu.

The analysis allows for qualitative detection of COVID-19 and two common strains of this year’s flu. Results are delivered within 48 hours of receiving the individual’s respiratory specimen, which is collected through a nasal swab. Results can provide meaningful information to each the patient, their family, and their healthcare provider to inform treatment and guide management. 

Further information about BG’s combination test can be found at

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