HCA Healthcare experts urge flu vaccine to help avoid ‘twindemic’

Man receiving flu vaccine
Dr. Jonathan Perlin, HCA Healthcare’s president of clinical operations and chief medical officer at HCA Healthcare receives his annual flu shot. October 2020 (Nashville, Tenn.)

The 2020-2021 flu season is here, and HCA Healthcare experts continue to urge the public to take action to protect themselves and others. With the looming threat of flu season colliding with the COVID-19 pandemic, learn why the flu shot is critically important this year and what vaccine options are available…

A male doctor showing a female patient a form on a clipboard
Make plans to get vaccinated early in fall, before flu season begins.


[ twin-dem-ik ]


Twindemic refers to the dual threat of a severe flu outbreak on top of the COVID-19 pandemic in the fall and winter of 2020

While the flu vaccine is an important preventative measure every year, it is arguably more important than ever in the midst of the COVID-19 pandemic. By getting a flu vaccine, you are helping to protect yourself and others from the flu. Since COVID-19 is also a threat this winter, it is important to do what we can to lower our risk of getting ill.

Did you know?

The Centers for Disease Control and Prevention (CDC) estimates that during the 2019-2020 influenza season, the flu vaccination prevented an estimated 7.52 million flu illnesses, 3.69 million flu-associated medical visits, 105,000 flu hospitalizations and 6,300 flu deaths.

“While we wait for COVID vaccines to be broadly available, the flu remains the number one cause of vaccine-preventable death in the United States,” explains Dr. Jonathan Perlin, president of clinical operations and chief medical officer at HCA Healthcare.  “By getting your flu shot and following the CDC’s advice to prevent the spread of COVID-19, you will be in the best position to protect yourself, your family and your community from illness this winter.”

In the Northern Hemisphere, we typically take cues from our Southern Hemisphere counterparts to predict when seasonal influenza will rise and peak. In years past, the Southern Hemisphere generally has its flu season from April to September. In the Northern Hemisphere, cases rise during the fall months and peak between December and January.

This year the good news – yes, good news – is that the Southern Hemisphere is experiencing a very mild flu season. For example, Australia reported a little over 21,000 cases of flu by the end of August, compared to nearly a quarter of a million at the same time in 2019. Experts theorize that this is due to an unprecedented number of people getting vaccinated and behavior related to the pandemic such as social distancing and mask wearing.

However, this is not the time to let our guards down.

“If both influenza and COVID-19 surge at the same time, it could be very devastating. A ‘twindemic’ is something that we can avoid,” said Dr. Kenneth Sands, HCA Healthcare’s chief epidemiologist.  “While what we’re seeing in the Southern Hemisphere is positive, we need everyone to come together and continue to do their part. We’re advising everyone over 6 months to get a flu shot, just as we do each year. By getting the flu vaccine, masking and distancing we can make it through flu season.”

In 2020, innovative measures are being stood up to ensure safe and convenient access to influenza vaccinations including drive-thru flu shot clinics and the U.S. Department of Health and Human Services authorizing state-licensed pharmacists to administer the flu shot to children starting at age 3.

How can you tell the difference between COVID-19 and seasonal flu?

COVID-19 and influenza are both contagious respiratory illnesses, caused by different viruses. COVID-19 is caused by infection with a new coronavirus (called SARS-CoV-2) and flu is caused by infection with influenza viruses: Types A and B. The symptoms can appear similar, however there are key differences that you need to be aware of.

Both 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 droplets made when people with the illness (COVID-19 or flu) cough, sneeze, or talk. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

It may be possible that a person can get infected by physical human contact like shaking hands or by touching a surface or object that has virus on it and then touching your mouth, nose, or possibly your eyes. Both flu virus and the virus that causes COVID-19 may be spread to others by people before they begin showing symptoms, with very mild symptoms or who never developed symptoms (asymptomatic).

According to the CDC, common signs and symptoms that COVID-19 and flu share include:

  • Fever or feeling feverish/chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue (tiredness)
  • Sore throat
  • Runny or stuffy nose
  • Muscle pain or body aches
  • Headache
  • Some people may have vomiting and diarrhea, though this is more common in children than adults

COVID-19 seems to spread more easily than flu and causes more serious illnesses in some people. It can also take longer before people show symptoms and people can be contagious for longer.

Another important difference is there is a vaccine to protect against flu. There is currently no vaccine to prevent COVID-19. The best way to prevent infection is to avoid being exposed to the virus.

Flu viruses can cause mild to severe illness, while COVID-19 can be more serious. A key difference in the two is that COVID-19 may cause a change in or loss of taste and smell, while that is not experienced with the flu.

Chart showing the symptoms of COVID-19, flu and cold
Is it a cold, flu or COVID-19? Learn about similarities and differences.

Available flu vaccines this season

Those who are interested in getting a flu shot have multiple options. Trivalent (three-component) and quadrivalent (four-component) flu vaccines are approved for the 2020-2021 flu season.

The CDC breaks down available flu shots below:

Trivalent flu vaccines include:

Quadrivalent flu vaccines include:

  • Standard-dose quadrivalent influenza shots that are manufactured using virus grown in eggs.  These include Afluria Quadrivalent, Fluarix Quadrivalent, FluLaval Quadrivalent, and Fluzone Quadrivalent. Different influenza shots are licensed for different age groups. Some are licensed for children as young as 6 months of age. Most influenza shots are given in an arm muscle with a needle. One quadrivalent influenza shot (Afluria Quadrivalent) can be given either with a needle (for people aged 6 months and older) or with a jet injector (for people aged 18 through 64 years only).
  • quadrivalent cell-based influenza shot (Flucelvax Quadrivalent) containing virus grown in cell culture, which is licensed for people 4 years and older. This season, all four of the vaccine viruses used in Flucelvax have been grown in cells, making the vaccine totally egg-free.
  • Recombinant quadrivalent influenza shot (Flublok Quadrivalent), an egg-free vaccine, approved for people 18 years and older.
  • quadrivalent flu shot using an adjuvant (an ingredient that helps create a stronger immune response), approved for people 65 years of age and older.
  • quadrivalent high-dose influenza vaccine (Fluzone High-Dose), licensed for people 65 years and older.

Stay vigilant to protect yourself and others

In addition to a flu shot, individuals can also help prevent getting the flu and help stop the spread of COVID-19 by taking these simple steps:

  • Wash your hands often with soap and water for at least 20 seconds. If soap and water are not available, use a hand sanitizer that contains at least 60% alcohol.
  • Avoid touching your eyes, nose and mouth.
  • Cover your nose and mouth with a tissue when you cough or sneeze. If you don’t have a tissue available, it is best to cough into your elbow.
  • Cover your mouth and nose with a mask when you are around others outside of your household and maintain a distance of at least 6 feet.
  • Clean and disinfect surfaces and objects that may be contaminated with germs daily.
  • Try to avoid close contact with sick people.
  • If you are sick with flu-like symptoms, the CDC recommends that you stay home for at least 24 hours after your fever is gone, except to get medical care or other necessities. (Your fever should be gone for 24 hours without the use of a fever-reducing medicine.)

Consider getting the annual flu vaccine to protect yourself and those around you. Call your healthcare provider today to schedule your flu shot.

About HCA Healthcare

HCA Healthcare, one of the nation's leading providers of healthcare services, is comprised of 183 hospitals and more than 2,300 sites of care, in 20 states and the United Kingdom. Our more than 283,000 colleagues are connected by a single purpose — to give patients healthier tomorrows.

As an enterprise, we recognize the significant responsibility we have as a leading healthcare provider within each of the communities we serve, as well as the opportunity we have to improve the lives of the patients for whom we are entrusted to care. Through the compassion, knowledge and skill of our caregivers, and our ability to leverage our scale and innovative capabilities, HCA Healthcare is in a unique position to play a leading role in the transformation of care.

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