Flurona: When the Flu and COVID-19 Collide

What is Flurona?

As the name suggests, Flurona is a combination of influenza and SARS-CoV-2 (the virus that causes COVID-19, a coronavirus). Because both viruses are so contagious, experts have been concerned that more people could be infected with both flu and COVID-19 at the same time, especially during flu season (in the US, flu season is considered autumn and winter). Flurona may be a new, catchy term but it is not a distinct disease, and is a co-infection usually transmitted by exposure or inhalation of droplets from both viruses.

Another term floating around in recent flu seasons is "Twindemic." This word refers to simultaneous high circulation rates of flu and COVID-19 (but not necessarily high rates of Flurona co-infection). A twindemic has been feared since the start of the COVID-19 pandemic but has not yet posed as big a threat as some feared (mostly due to viral mitigation efforts). However, with rates of flu peaking higher and earlier in other parts of the world, medical experts fear (and warn) that this flu season may be worse.

It is also important to note that flu and COVID-19 are similar in the sense that they are both respiratory viruses and share related symptoms, but flu and COVID-19 are not the same. In addition, the flu and COVID-19 are not the common cold. These viruses (on their own and as co-infections) can have serious health outcomes.

However, because of their similarities, it can be difficult to discover a co-infection without medical testing, and depending on symptoms and approaches, a patient may not be initially offered tests for both viruses. These notions may affect data collection.

Symptoms of flu include:

Fever and/or chills
Headache
Muscle or body aches
Sore throat
Fatigue
Cough
Runny nose
Congestion/stuffiness
Vomiting and/or diarrhea

Symptoms of COVID-19 include:

Fever and/or chills
Cough
Fatigue
Loss of taste or smell
Shortness of breath or difficulty breathing
Muscle or body aches
Sore throat
Runny nose
Headache
Chest pain
Pink eye (conjunctivitis)
Nausea
Vomiting
Diarrhea
Rash

It is clear to see that the symptoms of flu and COVID-19 overlap and illustrate potential confusion for which infection (or both) may be present in the body, but COVID-19 has some distinct symptoms: loss of taste and/or smell and shortness of breath. If the symptoms listed above become severe or are compounded by the following, seek emergency medical attention:

Difficulty breathing
Persistent chest pain or pressure
Inability to stay awake
New confusion
Pale, gray, or blue-colored skin, lips or nail beds

A diagnosis of co-infection with Flurona does not necessarily mean someone will be doubly or more severely sick, especially because many of the symptoms for each virus coincide. However, a co-infected body may be doing more work to fight a higher viral load.

Who is at risk for a co-infection of flu and COVID-19?

While a Flurona co-infection is rare, co-infections of two or more viruses are not. Studies have shown that about 43% of patients hospitalized with flu-like symptoms test positive for multiple viral infections.¹

Flu numbers were recorded as unusually low in 2020, which could have been because so many were infected with COVID-19 (and flu symptoms are similar), or because flu did not spread as much due to higher vaccine doses, as well as viral mitigation efforts like masking, hand hygiene, distancing, and isolation. In fact, flu vaccines were at a high for the 2020-21 flu season², according to the Centers for Disease Control and Prevention (CDC).

It is difficult to know exactly what numbers might be like this 2022-23 flu season, but flu numbers from Australia and the Southern Hemisphere (how the World Health Organization and CDC predict flu variants and transmission for the US and Northern Hemisphere) were high and concerning. Experts continue to stay alert and collect data, and medical professionals continue to recommend that people receive both influenza and COVID-19 vaccines (or boosters) before flu season begins in the US. See the current flu activity for your state with our weekly flu activity map.

Records show that younger patients (ages 14 - 41) are those getting Flurona most. This seems to be due to lower rates of vaccination for both flu and COVID-19 among this age group, as well as more social gathering and/or a reduction in preventative measures. Because of the age group affected, most cases were considered mild.

Young children are also at high risk for Flurona and other co-infections because of lower vaccination rates and more complicated prevention methods among this group. Children were hit the hardest by flu in Australia this season—a potential harbinger for children in the US this autumn and winter—and many young American children have not established immunity to influenza.

Sensitive groups like the elderly and those with underlying health conditions and/or compromised immune systems are advised to be vaccinated against both flu and COVID-19 to avoid infection and/or severe symptoms and outcomes, and to continue the mitigation measures used to combat most airborne illnesses. Certain flu vaccines are also recommended by the CDC for those aged 65 and over.³

It is also advised that pregnant people get a flu shot before they deliver. This ensures their infant can benefit in-utero from the antibodies needed to fight the flu since children under 6 months cannot receive a flu vaccine.

Because many prevention efforts (like distancing, masking, and avoiding large events) have been softened, the threat of the spread of both flu and COVID-19 may be higher this season. Prevention tactics undertaken because of COVID-19 are believed to be what kept flu numbers down in recent seasons.

Something else to note is that the height of flu season falls during many holiday celebrations in the US, where gatherings may be larger. Medical experts recommend getting a flu vaccine in October to best protect yourself and minimize the spread throughout the holiday and flu seasons.

What can you do to protect your health?

The preventative measures taken to ward off COVID-19 also prevent flu, so it is important to continue those habits: masking,⁴ washing hands, social distancing, and isolating when experiencing symptoms or knowing you have been exposed.

Getting vaccinated or boosted against both SARS-CoV-2 and the flu is your best bet to avoid severe sickness, hospitalization, and death. The CDC has approved getting flu and COVID-19 vaccines (or boosters) at the same time, and their experts have said getting both simultaneously will not weaken one's immune response to either virus. It is important to remember that vaccines take some time (usually about two weeks) to "kick in"/build immunity, so getting these protections before the start of flu season is crucial (again, October is usually recommended for the flu vaccine).

Because the predominant flu strain for the 2022-23 flu season is only a prediction in the US and Northern hemisphere, it is possible the influenza vaccine may not fully protect against the flu. However, a quadrivalent flu vaccine⁵ will still protect you from four types of flu viruses and severe flu symptoms, and this season's chosen vaccine/protective strains are reportedly a good match with the predominant circulating strains. A flu vaccine will not protect you strictly from COVID-19 (and vice versa), but studies have also shown that those vaccinated for influenza experience less severe health outcomes if they become infected with COVID-19.⁶

How are the symptoms (or treatment) different from coronavirus?

Flurona is not a super virus and the strains of each virus have not mutated together; they act on their own. However, each virus by itself, as well as the combination of symptoms, can be intense and lead to life-threatening effects such as septic shock, acute respiratory distress syndrome (ARDS), and organ failure. Influenza and SARS-CoV-2 viruses may show up in similar ways, but they affect the body differently. The loss of taste and/or smell is more synonymous with COVID-19 than the flu and is often a tell-tale sign of COVID-19, though testing is still important to confirm and know when to isolate.

COVID-19 alone can cause long-term effects known as long COVID-19, which can appear as an array of symptoms throughout the body's systems, which may include:

General symptoms

Tiredness or fatigue that interferes with daily life
Symptoms that get worse after physical or mental effort (also known as "post-exertional malaise")
Fever

Respiratory and heart symptoms

Difficulty breathing or shortness of breath
Cough
Chest pain
Fast-beating or pounding heart (also known as heart palpitations)

Neurological symptoms

Difficulty thinking or concentrating (sometimes referred to as "brain fog")
Headache
Sleep problems
Dizziness when you stand up (lightheadedness)
Pins-and-needles feelings
Change in smell or taste
Depression or anxiety

Digestive symptoms

Diarrhea
Stomach pain or nausea

Other symptoms

Joint or muscle pain
Rash
Changes in menstrual cycles

Long COVID-19 symptoms last long after a positive test or suspected COVID-19 case and are still being studied.⁷

Flu can also cause serious complications, especially for those in high-risk groups. Complications or long-term effects of flu may include:

Pneumonia
Bronchitis
Asthma flare-ups
Heart problems
Acute respiratory distress syndrome (ARDS)
Ear infections

Emergency signs related to flu can include:

Difficulty breathing or shortness of breath
Chest pain
Ongoing dizziness
Seizures
Severe weakness or muscle pain

Emergency signs related to flu in children can include:

Difficulty breathing and/or changes in skin or lip color (turning blue)
Chest pain
Dehydration
Severe muscle pain
Seizures

Pneumonia is a serious complication. For those ages 65+ and people with a chronic illness or weakened immune system, pneumonia can be fatal.

Treatment for Flurona depends on severity but is (unsurprisingly) similar to the treatment for influenza and COVID-19. Therapies like Tamiflu^® or antiviral pills such as Paxlovid™ may be prescribed to help to treat the co-infection. However, mild symptoms can be addressed using over-the-counter medicines and fever-reducers at home. If you do become infected or are experiencing symptoms of flu and/or COVID-19, it is important to isolate as to not spread either virus (or both), and to seek medical attention if symptoms become severe.

For more information

For more information about Flurona, see the resources below and/or speak with your healthcare provider.

For influenza and/or COVID-19 vaccination locations, you can search here: Find vaccine locations near you.⁸

MyFluVaccine is here to help you prepare for flu season and answer any questions related to the flu vaccine. Contact us today for more answers.