Viral Overload

Learn how to navigate flu season in the time of a global pandemic

Written by Lauren B. Johnson

Coughing, sneezing, fevers, chills and aches—you’re likely familiar with the flu’s hallmark symptoms, since this seasonal sickness infects between nine-million and 45-million people annually. But what do you really know about this family of viruses? Maybe even more pressing, what happens when flu season overlaps the COVID-19 pandemic?

The impending upper respiratory season presents new challenges and concerns with the double whammy of influenza and coronavirus. To allay our fears and help us prepare, we talked with Roper St. Francis Healthcare affiliated internist Dr. Robert Oliverio about the flu and what to expect from this virus in the following months.

Meet the Flu

“Flu,” short for influenza, spreads through respiratory droplets (coughing and sneezing) and fomites (surfaces that carry disease). The resulting respiratory illness causes a runny nose, coughing, body aches and sometimes a fever for several days and up to two weeks. Further complications such as sinus and ear infections and viral pneumonia may arise in young children, seniors, pregnant women and those whose immune systems are already taxed by cancer, diabetes, heart disease, asthma or COPD. Such stress on the body also increases the risk of a heart attack or stroke.

Two flu types—A and B—promote these seasonal epidemics, hospitalizing as many as 810,000 people annually. Under the more common flu A exist many subtypes identified by their combination of the proteins hemagglutinin (H) and neuraminidase (N)—H1N1, for example. Once inside a host, the virus replicates and those surface-level proteins begin to change.

These small genetic shifts make the virus more infective and up its chances of survival. “If a mutation is subtle, we may possess residual immunity or cross-protection from previous exposures, but we’re never completely immune to a new strain,” explains Dr. Oliverio. “Sometimes, though, a strain transforms significantly enough to form a new subtype, known as an antigenic shift, which can lead to a pandemic flu season.” Without any residual immunity, a global outbreak of a novel flu A virus occurs, putting even healthy young adults at risk for serious complications. (Sound familiar to the COVID-19 eruption?)

Influenza A infects a variety of species, including humans, cattle, dogs, birds and pigs, allowing the virus to spread and change genetically in very short order. Influenza B shifts more slowly, as it can only live in humans

What to Expect

We can’t know with certainty what will happen with this year’s flu season. “Like the stock market, past performance doesn’t predict future performance,” Dr. Oliverio explains. We can, however, understand the upside and downsides of facing flu and COVID-19 simultaneously.

Dr. Robert Oliverio
(Photograph by Chelsie Mummert)

 First, the good news. “What we’re already doing to mitigate COVID-19—social distancing, hand washing and masking—will also reduce flu spread,” says Dr. Oliverio. As evidence, the World Health Organization reported a swift drop in lab-confirmed flu cases beginning in early April, just a few weeks after declaring the coronavirus pandemic. As a result, the 2019 to 2020 flu season tapered off six weeks earlier than usual.

 The not-so-good news? “You can be infected with influenza and COVID-19 at the same time, with the potential to get very sick,” explains the internist. “We also don’t want a situation in which the number of flu and COVID-19 patients requiring ICU beds overruns hospital capacity.”

These risks make receiving the flu vaccine especially vital this year, though in response to ever-changing flu subtypes, we should be doing this each year anyway. Both the shot and nasal spray use noninfective proteins (meaning they won’t make you sick) to trigger an immune response. This all-points bulletin shows our bodies distinguishing characteristics (remember those Hs and Ns?) of the strains experts believe will dominate that season. To make such predictions, the Centers for Disease Control and Prevention (CDC) maintains a database of recent antigenic shifts then develops a vaccine for the two or three most prevalent. “It’s a bit of a shotgun approach,” notes Dr. Oliverio, “but they’re trained shooters.”

 Since immunity can take two weeks to build up following the flu vaccine, the doctor recommends everyone six months and older get the vaccine about a month before the flu usually appears. The CDC points to September and October as prime times for inoculation, but it’s never too late. Vaccinations will continue to be administered as long as flu viruses circulate, into January or beyond, and one dose should be enough to last all season.

“Flu pandemics happen rarely. Four have happened in the last 100 years [1918, 1957, 1968 and 2009], but experts agree another one is inevitable.” –Centers for Disease Control and Prevention

The Good Fight

“The key to treatment is early diagnosis,” says Dr. Oliverio, explaining that influenza works in two phases, replication and response. In the replication phase, the virus is multiplying inside its host. Scientists have developed four medications that decrease the ability of the virus to replicate, with oral oseltamivir (better known as Tamiflu) most commonly prescribed. When taken within two days of feeling sick, this medication can lessen the severity and duration of the illness.

“After 48 hours, however, the flu has taken hold,” says the doctor. Once the body begins responding to the virus, usually with a high fever and mucus secretion, supportive care becomes the focus. He recommends over-the-counter medications to decrease fever, stuffy nose and cough as well as plenty of hydration.

 Despite our best efforts, influenza will still strike. Thankfully, health professionals know a great deal about identifying and treating this particular virus. For the 2020 to 2021 flu season, doctors can test a single nasal swab sample for influenza A, influenza B and COVID-19. A joint test not only saves time and materials, it also provides public health officials with important information about viral spread, coinfection and prevention.

“The only certainty about this upcoming flu season is that we can make a significant change in how the virus infects and affects millions of people through our actions,” says Dr. Oliverio. “Vaccinations, masking, social distancing and hand washing—these are the levers we can pull.

What we’re already doing to mitigate COVID-19—social distancing, hand washing and masking—will also reduce flu spread. —Dr. Robert Oliverio

Influenza vs. COVID-19

Fever, cough, difficulty breathing, fatigue, sore throat, stuffy nose, body aches, nausea, diarrhea—influenza and COVID-19 share a long list of similar symptoms that present in varying degrees of severity. However, there is one marked difference between these contagious respiratory illnesses: COVID-19 causes a sudden loss of taste or smell. Because so many signs of these two viruses overlap, testing may be needed to confirm a diagnosis.

Flu vaccine manufacturers project they will provide 194- to 198-million doses this season, breaking the record high of 175 million set last year

Where and how to get your flu vaccination this year:

  1. The influenza vaccine can be obtained as usual at doctors’ offices, clinics, pharmacies and health departments.
  2. When you go, wear a mask, stay six feet from others, refrain from touching your face, use hand sanitizer when leaving and wash your hands with soap and water for 20 seconds upon returning home.
  3. To avoid exposing others to COVID-19, people with suspected or confirmed coronavirus should postpone vaccinations until a medical provider indicates they can discontinue isolation.
  4. Visit to find a nearby vaccination site. The web page can search for standard flu shots as well as specialized options such as nasal spray (for ages two through 49 who are not pregnant), egg-free (for people with allergies), and high-dose (for seniors age 65 and up)

One response to “Viral Overload”

  1. Thank you for the greatly needed information regarding the overlap of the flu season and Covid. This information emphasizes the importance of continuing to follow all necessary guidelines to prevent seasonal flu and Covid. It’s important to be reminded.

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