What We Know About Florona: the New COVID-19 and Influenza Compound Infection

It is not a variant, but a double infection.
Maia Mulko
The COVID-19 virus cell.peterschreiber.media/iStock

The Omicron variant seems to have sped up the COVID-19 pandemic around the world, increasing rates of infection and transmission. By December 21, 2021, approximately 73% of COVID-19 cases in the U.S. were due to the Omicron variant. 

Scientists are concerned about Omicron because it is more contagious and is able to bypass at least some of the body’s immunity, even in vaccinated people. The variant is thought to carry around 50 amino acid-altering mutations and at least 10 silent mutations in coding and non-coding regions. The majority of these mutations are found in the Spike protein, which is a major modulator of infectivity and immune evasion. 

However, the evidence so far suggests that while transmissibility, partial vaccine evasion, and the rate of virus replication are very high with Omicron, the good news is that vaccination and booster shots seem to be effective at preventing severe illness and hospitalization.

healthcare worker preparing to extract a dose of vaccine
Source: Asian Development Bank/Flickr

However, the emergence of Omicron has also led to cases of 'Delmicron' - a simultaneous infection with both Delta and Omicron variants. Very little is known about Delmicron, including how common it is, although it may cause more severe symptoms than Omicron. 

And just when we thought things couldn’t be worse with this pandemic, at the beginning of the new year, Israel reported its first case of Fluona - a rare double infection of seasonal flu and COVID-19 at the same time. The two infections were found in an unvaccinated pregnant woman who had mild symptoms.

Some reports suggested this was the first such dual case in the world, but there were reports of patients with both flu and COVID-19 reported in the U.S. as early as spring 2020. 

What are the symptoms of florona?

Florona has set off the alarms among medical researchers because, while last winter there were fewer than usual numbers of flu cases, due to COVID-19 restrictions, this year has seen a spike in the number of flu cases in some areas. In Israel, there are around 2,000 people hospitalized with the flu, leading to fears that large numbers of flu cases and COVID-19 cases could overwhelm hospitals.

Both COVID-19 and the flu are respiratory diseases that attack the airways. They also have very similar symptoms. Both with COVID-19 and the flu, people may have a high fever, runny nose, loss of appetite, sore throat, cough, headache, and fatigue. Florona does not so far appear to make these symptoms worse than with an individual infection. 

So what’s all the fuss about? Many people may have mild symptoms, especially if they’re vaccinated, but both the flu and COVID-19 can have serious consequences. Both viruses can cause pneumonia, swelling of the tissue in the lungs which can be a very serious condition. Pneumonia can be caused by either a bacterial, viral, or fungal infection and the inflammation of the airways causes breathing difficulties and can damage the lungs. This is one main reason why some COVID-19 and flu patients end up requiring mechanical ventilation. 

Source: BruceBlaus/Wikimedia Commons

The flu virus can also cause an inflammation of the heart, muscles, and brain, and lead to secondary bacterial infections that increase the risk of sepsis and multi-organ failure. 

While many of us get through the flu every year without complications, the flu virus is more dangerous for older people, pregnant women, babies, and very young children, and people with chronic conditions such as asthma, diabetes, cancer, HIV/AIDS, and heart disease. This is why it’s important for everyone, but particularly for these people, to be vaccinated not only against COVID-19 but also against the flu.

Especially with the COVID-19 pandemic, people don’t generally pay attention to flu-related hospitalizations and casualties, but there are plenty every year. In the US, there were an estimated 20,000 deaths from influenza in 2019-2020. 

The most worrying part is that both diseases can spread to others while the carrier is still asymptomatic. Flu symptoms can appear 1 to 4 days after infection while COVID-19 symptoms can appear 5 to 14 days after infection. It is also possible that exposure to both viruses at the same time could cause added stress to your immune system, as it would have to fight two different viruses simultaneously. 

How is florona diagnosed?

Given that both COVID-19 and the flu have very similar symptoms, doctors can’t diagnose Florona solely based on these signs. Due to the COVID-19 pandemic, if you have symptoms you’ll most likely be tested for COVID-19, but the PCR tests that can detect an active COVID-19 infection can't detect the flu virus because it is genetically different.

This makes the Florona diagnosis more difficult as patients would need to be tested for two different viruses to confirm the presence of both.  This is actually how the first Florona case was confirmed in Beilinson hospital in Petah Tikva, Israel. The carrier was a pregnant woman who went into labor at Rabin Medical Center. 

"She was diagnosed with the flu and coronavirus as soon as she arrived. Both tests came back positive, even after we checked again," said Professor Arnon Vizhnitser, the director of the Rabin Medical Center’s gynecology department. 

She was not vaccinated against either pathogen, but luckily she is recovering from the double infection. 

This happened in the middle of a seasonal influenza epidemic in Israel. According to the ICDC (Israeli Center for Disease Control) and the country’s Ministry of Health, hospitals have treated almost 2,000 flu patients in the last week of 2021. 

Apart from this, Israel is having a weekly average of more than 5,000 COVID-19 infections.

In this context, Israeli authorities believe that there are more cases of florona in the country but doctors have not yet detected them so they have gone unreported. 

What is the treatment for florona?

There is no treatment for florona other than the treatments already used for COVID-19 and for the flu. For the flu, there is no treatment for the virus itself, but most people treat the symptoms with rest, over-the-counter medications to reduce fever and pain, and plenty of liquids. 

Only now there’s something that can be called a treatment for COVID-19 patients, the Pfizer COVID-19 antiviral pills, called Paxlovid, that were recently given emergency use authorization by the FDA. In clinical trials, Paxlovid was found to reduce the risk of hospitalization or death from the disease by roughly 89%. The pill can be used to treat mild to moderate cases of covid-19. However, it is too soon to tell if they will be effective against all of the symptoms of florona.

The main strategies for both influenza and Covid-19 remain prevention. In addition to Covid vaccinations and boosters, people are being encouraged to get flu shots. In Israel, the Ministry of Health of Israel has advised flu vaccinations for anyone over the age of six months and other countries are also expanding the availability of flu shots.

Administration of flu vaccine
Source: Government of Prince Edward Island/Flickr

A British study has recently found that it is safe for people to receive a COVID-19 vaccine and a flu shot at the same time. It was also shown that doing so does not negatively impact the immune response produced by either shot. The research comes as Britain and other countries are bracing for a possible surge in flu cases as COVID-19 restrictions are eased. If there is a surge in flu cases, there is also the possibility that Florona will also become more common.