When symptoms like fever, cough, sore throat, or sniffles appeared during the peak of the COVID-19 pandemic, people may have panicked and searched online, asking, “Is this COVID-19 or the flu?”
Even though the COVID-19 Public Health Emergency has ended1, it’s still a good idea to know how to prevent getting sick and the distinctions and similarities between COVID-19 and influenza. The information could be especially useful because COVID-19 case spikes, which may include the introduction of new variants, coincide with flu season, which runs from October to May. This could lead to what is known as a “twindemic,” or the co-circulating of both viruses.
What are the Similarities Between Flu and COVID-19?
It’s important to comprehend why it can be challenging to differentiate between the two illnesses before going over their differences: Both COVID-19 and influenza are respiratory infections that are communicative and can cause fever, coughing, runny noses, sore throats, body aches, vomiting, and diarrhea, among other symptoms.
Testing may be required to provide an accurate diagnosis because it may be difficult to distinguish between COVID-19 and the flu based only on symptoms. As a result, your healthcare provider may be better able to determine how to treat the illness.
Similar Spread Patterns Between Flu and COVID-19
Both viruses are spread by intimate contact with an infected person. When we cough, sneeze, or talk, tiny and large virus-containing particles enter the air and spread COVID-19 and the flu. Infections can spread by these particles landing in noses and mouths or by breathing them in through the respiratory system.
It is feasible for an individual to carry both the flu and COVID-19 infections and transmit both viruses prior to exhibiting any symptoms or during mild symptoms. This also holds true for those who are asymptomatic, or who never experience symptoms.
Although less common, surface transmission—touching an infected surface or object and then touching your mouth, nose, or eyes—is still a viable method of COVID-19 and influenza virus transmission.
Different Viruses, Different Patterns
Although the flu and COVID-19 have many of the same symptoms and can spread through some of the same channels, these infections are caused by two distinct viruses. That’s why they differ in a few important ways.
For example, COVID-19 is considered to be more transmissible and to cause more severe infections.3. Compared to the flu, COVID-19 has a higher chance of “super spreader” events.
People who have the flu are usually contagious for one day or more before they exhibit symptoms, and they are most contagious during the first three to four days of the illness. People who have been diagnosed with COVID-19 are at highest risk of spreading the virus one day prior to the onset of symptoms, and they may remain contagious for up to eight days following the onset of symptoms.
Certain distinct telltale symptoms, such as loss of taste and smell,5 persistent symptoms,6 red/swollen eyes, and skin rashes, may also be present with COVID-19, depending on the variant.
Furthermore, there are notable distinctions in the onset and molecular mechanisms of these two diseases.
SARS-CoV-2 has (so far) been a persistent presence, or “endemic,” in contrast to influenza, which is seasonal, according to Santiago Lopez, U.S. Senior Medical Director, Medical and Scientific Affairs Lead at Pfizer. “At this point, it is considered endemic, but some data suggest peaks when it’s more prevalent, which mimics a seasonality.”
He goes on, “Compared to influenza, SARS-CoV-2 changes at a substantially faster rate. While there are seasonal “strains” of the flu that differ slightly from one another, SARS-CoV-2 exhibits far more dramatic “variants.”
What kinds of complications may occur?
“There is a chance of long-term or severe illness with both COVID-19 and the flu,” says Verna Welch, Global Senior Medical Director, Influenza Medical and Scientific Affairs Lead at Pfizer. She notes that in addition to the symptoms and signs commonly associated with the flu, it has also been connected to a number of other illnesses, including sinus infections, pneumonia, ear infections, and potentially meningitis.
Beyond that, a number of non-infectious illnesses are linked to the flu according to the Centers for Disease Control and Prevention (CDC). These illnesses include pneumonia, sinus and ear infections, inflammation of the heart, brain, or muscles, and possibly multiple organ failure.
In a similar vein, a more serious case of COVID-19, known as “severe COVID-19,” may necessitate hospitalization, intensive care, or a ventilator, and it may also increase the risk of death. Older adults and those with underlying medical conditions like cancer, diabetes, or heart disease are more likely to contract severe COVID-19 infections.
Serious side effects, such as blood clots in the veins and arteries of the heart, brain, legs, or lungs, can occur in some COVID-19 patients. When children and adults contract COVID-19, a rare but serious complication called multisystem inflammatory syndrome may arise.
There’s a chance that some COVID-19 patients’ symptoms will linger considerably longer because of a condition called “long COVID.”Eleven
“Many times these viral diseases manifest similarly to chronic fatigue syndrome, exhibiting signs like exhaustion, cognitive disorientation, and malaise after physical activity,” Dr. Welch says. This is also not specific to COVID-19; it has also been reported in cases of the flu and other viruses.
The key is prevention, she stresses. “Avoiding infection in the first place is the best way to avoid long-term COVID, long-term flu, or post-infection illnesses in general.”
How are COVID-19 and the flu treated?
According to the CDC, mild flu symptoms usually don’t require treatment. Over-the-counter and FDA-approved prescription medications can be taken to treat flu symptoms, lessen the severity of the illness, and lower the risk of complications in more severe cases or for those who are at high risk of complications.
Certain patients, such as those who are highly susceptible to a serious infection, hospitalization, or even death, can also be treated with medications for mild to moderate COVID-19.
Tips for Preventing COVID-19 and the Flu
Given the similarities between COVID-19 and the flu, there may be some overlap in the approaches to illness prevention:
Getting vaccinated: There are vaccines that may help reduce the risk of COVID-19 and influenza-related serious illness.3 For everyone over six months old (with rare exceptions), the CDC advises getting the annual flu shot and maintaining current COVID-19 vaccinations in order to potentially lower the risk of serious illness, hospitalization, and death.
However, what does it mean to be “up to date”?
“We don’t yet know at what frequency we’ll need to vaccinate for SARS-CoV-2,” says Lopez. “Vaccination against the flu is annual.” “We are currently developing vaccines without any set schedule, just whenever new variants call for them.”
lowering the risk: Some important tactics to potentially help lower the risk of catching or spreading the flu include wearing a mask, washing your hands frequently, and avoiding contact with people if you feel sick.
Knowing the differences and similarities between COVID-19 and the flu as well as how to stay healthy could help reduce your risk of becoming ill.
