Influenza and Covid-19: How are they different?

Flu or coronavirus? As the fall season approaches, the challenge of distinguishing a common flu from a COVID-19 infection has become more complex than ever.

If in the early years of the pandemic, the loss of taste and smell (anosmia and ageusia) represented an almost unmistakable warning sign for COVID-19, this is no longer the case today.

As highlighted by the analysis for the new season, the SARS-CoV-2 variants currently in circulation (such as strains derived from “Pirola” and JN.1) cause symptoms much more similar to a strong cold or to classical influence.

Cough, sore throat, runny nose and fever are common to both conditions, making diagnosis based on symptoms alone almost impossible and the use of diagnostic tests is the only real solution.

But before we get to the differences between Covid-19 and seasonal flu, we need to analyze the different variants of Covid currently in circulation.

The new COVID variants

The COVID-19 landscape for the 2025-2026 season is dominated by the so-called "new variants." As reported by the main monitoring sources, these are mainly strains descended from the "Pirola" variant (BA.2.86), with a clear predominance of the variant. JN.1 and its sublineages.

Their main feature is a high immunofuge, which allows them to infect even people who have already been vaccinated or have recovered from previous infections.

It is precisely because of these variants that the symptomatic picture has radically changed: they mainly attack the upper respiratory tract (nose, throat) and only rarely cause loss of taste and smell.

The updated vaccines for the fall 2025 campaign have been specifically formulated to offer maximum protection against these strains.

Symptoms compared

According to the latest health sources, including doctors from theInfant Jesus Hospital, There is no longer a single symptom that allows one of the two diseases to be excluded with certainty.

Both can present a very similar pictureThe common symptoms are practically the same with slight differences:

• Temperature;
• Dry cough;
• Sore throat (more common for Covid-19);
• Cold and stuffy nose (more common with Covid-19);
• Muscular pains and joint problems (with a higher prevalence for seasonal flu);
• Heachache;
• Tiredness (Asthenia);
• Loss of smell and taste (rare for the flu and now very rare also for Covid-19);
• Gastrointestinal symptoms (possible especially in children in both cases).

What are the causes? Different viruses

Although the symptoms are similar, the diseases are caused by completely different viruses:

• Influenza: It is caused by the vinfluenza A viruses e influenza B virus, which change rapidly every year (which is why the vaccine must be repeated).
• COVID-19: It is caused by the SARS-CoV-2 virus, a coronavirus. Its constant mutations generate new variants that can partially evade previous immunity.

In both cases, transmission occurs primarily through respiratory droplets from infected individuals, such as when they sneeze, blow their nose, or talk.

Even touching surfaces contaminated by droplets can be dangerous, which is another reason to use them. disinfectant gels, even homemade onesIn the case of Covid-19, sneezing and a stuffy nose are common; with the flu, they sometimes occur.

How to diagnose

Given the overlapping symptoms, self-diagnosis is inadvisable and unreliable. The only way to get a definitive answer is to undergo a diagnostic test.

1. Rapid antigen swab: It's the fastest solution (results in 15 minutes) for detecting the presence of virus antigens. It's highly reliable in the presence of symptoms and a high viral load.
2. Molecular swab (PCR): It remains the gold standard for accuracy. It analyzes the presence of viral RNA and can detect infection even at low viral loads.
3. Multiplex Tests: Tests that can simultaneously detect the presence of a single swab are becoming increasingly widespread in pharmacies. Influenza A, Influenza B, and COVID-19, offering a complete and rapid diagnostic picture.

Treatments and cures

For both influenza and most cases of COVID-19 in vaccinated, non-risk people, therapy is symptomatic:

• Rest: It is essential to allow the body to fight the infection.
• Hydration: Drink plenty of fluids (water, herbal teas, broths) is essential.
• Symptomatic drugs: Antipyretics such as paracetamol for fever and nonsteroidal anti-inflammatory drugs (NSAIDs) such asibuprofen for muscle pain and headaches, always after consulting your doctor.

For those at risk (elderly, immunocompromised, people with chronic diseases), there are specific treatments:

• For the flu: Antiviral drugs (such as oseltamivir) may be prescribed, preferably started within 48 hours of the first symptoms.
• For COVID-19: Specific antiviral drugs (such as Paxlovid) are available which, if taken early, significantly reduce the risk of severe illness and hospitalization.

How to prevent it

The most effective prevention strategy for autumn-winter 2025-2026 is based on two pillars:

1. Vaccination
2. Hygiene measures

Here's how to prevent the flu and Covid-19.

Flu vaccine

Sars-Covid-19 vaccine

At the same time, for those at risk, an updated Covid-19 vaccine is available, formulated to cover the most recent variants (such as JN.1) and protect against severe disease and, therefore, the rare but possible dangerous courses of the disease.

Hygiene measures

Good prevention against viruses in general starts with proper hygiene measures in everyday life. In particular, it's important to remember to:

• Wash your hands frequently and carefully, with soap and water or hydroalcoholic gel.
• Masks: Although no longer mandatory, masks remain a fundamental protective tool. They are strongly recommended in crowded and indoor spaces, on public transport, and are essential for those visiting hospitals, nursing homes, or vulnerable individuals.
• Ventilation: Regularly ventilating closed spaces helps disperse the viral load.

Read also:

• Coronavirus: How to protect dogs and cats. Knowing they don't infect others.
• Coronavirus: How to clean cell phones and smartphones. And use them without fear.
• Coronavirus, how much we miss kisses. Now we understand their importance.