Difference between COVID-19 and Influenza
The novel coronavirus only came into existence a year ago. There is still a lot of confusion surrounding the disease, given its likeliness to other respiratory diseases like the flu.
Insufficient test results have given rise to innumerable rumours surrounding the disease, which makes understanding the difference between COVID-19 and influenza harder by the day.
We tried compiling all available data that can help you distinguish between the two and get the correct treatment.
Have a look at the brief overview to help yourself in such trying times.
Which virus families cause COVID-19 and influenza?
| Details of the causative agent | COVID-19 | Influenza |
| Virus family | Coronaviridae | Orthomyxoviridae |
| Virus type | SARS-CoV-2 | Human influenza A and B |
SARS-CoV-2 is a novel virus, and yet much is unknown about it. The total number of coronavirus strains remain unknown at present. On the other hand, one of the flu virus strains, influenza A, already has 131 sub-strains detected to date. This is made possible due to the numerous subtypes of its NA and HA surface proteins which leads to a large number of combinations.
Since both COVID-19 and influenza are respiratory diseases caused by viruses, they are transmitted in a somewhat identical manner.
Read more about Coronavirus:
COVID-19 & influenza – Transmission
Now, there are plenty of similarities when it comes to the way each of these diseases spreads. Both are highly contagious and can be transmitted from person to person contact. However, there have been some recent significant transmission trends governing the difference between coronavirus and influenza.
Here, we present the similarities and contrast between the two in the following table.
| Transmission factors | COVID-19 | Influenza |
| Mode of transmission | Droplet-borne through talking, coughing, and sneezing, Touching your face after touching a contaminated surface | Droplet-borne through talking, coughing, and sneezing, Touching your face after touching a contaminated surface |
| Maximum transmissible distance | 6 feet | 6 feet |
| Pre-symptomatic transmission | 24-48 hours prior to the onset of symptoms | Within 3-5 days of infection |
| Incubation period | 2-5 days, some patients can also remain asymptomatic for up to 14 days | 1-3 days |
| Serial interval (the period between 2 successive cases) | 5-6 days | 3 days |
| Reproductive number | 5.7 | 0.9-2.1 |
| Commonly affected age groups | Adults (60+ years), individuals with underlying health conditions, individuals aged below 20 years are mostly asymptomatic carriers | Children (0-17 years), pregnant women, individuals with weak immunity or pre-existing ailments, the elderly |
| Attack rate | 12.4% in adults aged 60+ years among households contacts | 9.3% in children, 8.9% in adults aged 18-64 years, 3.9% in adults ages 65+ years |
| Mortality rate | First observed to be 3.4%, then decreased to 1.0%-0.9% | Less than 0.1% |
| Pandemic probability | SARS-CoV-2 has already caused a pandemic since it is new to our immune systems and has no existing treatment | Evolving zoonotic subtypes of influenza strains can lead to a new pandemic |
How to understand if your symptoms are of COVID-19 or influenza?
The acute similarity between symptoms of COVID-19 and influenza can often make it difficult for individuals to differentiate one from the other in the early stages. Unfortunately, this also reinforces the fact that there is no sure way to understand the difference between COVID-19 and influenza except medical diagnosis. However, here is a chart with a brief overview of the various possible symptoms and their severity in each disease.
| Symptoms | COVID-19 | Influenza |
| Cough | Severe, dry, and persistent coughs that can cause shortness of breath | Mild, dry coughs |
| Fever | For 3-4 days | 2-7 days |
| Breathing problem | Very prominent, can be severe | Mildly possible |
| Sore throat | Very prominent | Possible |
| Fatigue and weakness | Prominent gradually | Prominent from the beginning |
| Repeated shaking with chills | Possible | Rare |
| Muscle aches | Possible | Prominent, can be severe |
| Runny nose or blocked nasal passage | Common | Possible |
| Headache | Common | Prominent |
| Nausea, vomiting, diarrhoea | Common | Common |
| Brain fog | Possible | Rare |
| Unique symptoms | Sudden change in or lack of smell and taste, Multisystem Inflammatory Syndrome (MIS-C) in children | None |
| Complications | Fatal Pneumonia, Microvascular thrombosis of the toes, Blood clots in arteries and veins of lungs, heart, or brain | Curable pneumonia |
In addition to the complications mentioned above, there are certain common severities observed in both diseases. These are:
- Acute respiratory distress syndrome (ARDS)
- Cardiac arrest and stroke
- Secondary bacterial infections
- Sepsis
- Aggravation of chronic medical conditions
- Multi-organ failure
These complications can be further accelerated in patients with pre-existing medical conditions and often lead to fatalities, showing little to no response to treatment. Early diagnosis and understanding the difference between COVID and influenza can help greatly. Then, depending on your diagnosis, seek available treatment options from healthcare professionals.
Now that you know the answer to what is the difference between flu and Covid, let’s take a look at these conditions’ treatments.
What are the different treatment options available for COVID-19 and influenza?
Although influenza viruses have been around for a long while and SARS-CoV-2 is a brand new virus, both are constantly evolving as new strains, and sub-strains are detected.
However, the major difference between the cure for COVID-19 and influenza is that the latter can be treated with already available FDA-approved medications and vaccines.
Unfortunately, the same cannot be said for the novel coronavirus as scientists and doctors continue to treat critical patients with trial drugs.
Here are all the modes of treatment available for both diseases to date.
| Treatment options | COVID-19 | Influenza |
| Antiviral drugs | Phase 3 trial drug , 1) Remdesivir | FDA-approved drugs Baloxavir marboxil (Xofluza) 1) Zanamivir (Relenza), 2) Peramivir (Rapivab), 3) Oseltamivir phosphate (Tamiflu) |
| Vaccines | Phase 3 trial vaccines - 1) Covishield, 2) Covaxin, 3) Pfizer, 4) Moderna, 5) Sputnik V | FDA-approved vaccines - 1) Inactivated influenza vaccines (IIV), 2) Live attenuated influenza vaccines (LAIV) |
| Others | Convalescent plasma therapy | None |
Besides the mentioned treatment options, supportive care is a must for both COVID-19 and influenza. This includes:
- Drinking plenty of fluids to stay hydrated
- Getting enough rest
- Taking additional medications for symptomatic treatment, as prescribed by professionals
- Taking prescribed dietary supplements comprising essential nutrients
- Mechanical ventilation for severely affected individuals
You know what they say, right? Prevention is better than cure.
Given the current scenario where the second wave of COVID-19 has hit hard amidst the flu season in India, it is best to practice the said precautionary measures. These include wearing a mask, observing physical distancing, and washing/sanitising your hands frequently. Despite the difference between COVID-19 and influenza, these little preventive measures can help protect you from both.
Is it important to get the flu shot during the ongoing pandemic?
Flu shots can keep people safe from being afflicted with influenza. This, in turn, will keep medical resources free for those suffering from Covid-19. However, if you are already suffering from Covid-19, medical practitioners recommend waiting for at least ten days from the day when you started showing symptoms. After these 10 days, you can seek the flu shot.
Frequently Asked Questions
Can you show symptoms for both influenza and COVID-19 simultaneously?
Yes, it is possible to undergo both of these infections at once.
Does the flu vaccine protect me from catching the novel coronavirus?
No, the flu vaccine cannot prevent you from getting infected with COVID-19 since the two are caused by completely different viruses.
Why is Covid-19 considered more dangerous than an influenza affliction?
According to researchers, the likelihood of death from Covid-19 is more than triple than that from an influenza infection. The study also discovered that Covid-19 infection also carries almost a 1.5 times increased chances of ICU admission when compared to influenza.
Can I develop COVID-19 from influenza?
Influenza and COVID-19 are caused by two different kinds of viruses. Neither can the flu virus develop into the coronavirus, nor can vice versa happen. However, instances of coinfection have been reported, where an individual is affected with more than one respiratory virus.