Is coronavirus worse than flu? How deadly and contagious is coronavirus compared to regular flu

With countries around Europe shutting down, some have asked why coronavirus is being treated so much more seriously than the regular flu.

While the flu kills thousands of people every year, it is much more of a known quantity than the coronavirus.

Although the two present a lot of similar symptoms, there is significant evidence to suggest that coronavirus poses a very different threat to seasonal flu.

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How are coronavirus and regular flu different?

For people who are not elderly and do not have underlying health conditions, coronavirus is likely to present itself much in the same way as the regular flu does – leading to a runny nose, sore throat and a cough.

While some people show no symptoms at all, the World Health Organisation (WHO) have said that, based on data from the initial outbreak in China, they believe these cases to be rare.

However, there are also some major differences between the two illnesses, given that they are the product of two different virus families.

WHO Director-General Tedros Adhanom Ghebreyesus sought to clarify the matter on Tuesday 10 March, stating: “This virus is not SARS, it’s not MERS, and it’s not influenza. It is a unique virus with unique characteristics.”

While it’s thought influenza viruses have been around for thousands of years, Covid-19 is a brand new strain of coronavirus, the family of viruses from which we get the common cold.

“There is population immunity to many strains of the flu,” said Amesh Adalja from the John Hopkins Centre for Medicine. “There are four other strains of the coronavirus, but the attack rate of this virus is relatively high as there is no immunity to it.”

As it will likely take at least a year before a coronavirus vaccine can be developed and made widely available, our means of containing its spread are much more limited.

We also have antiviral medicines for the flu which can reduce symptoms and shorten the duration of the illness. While antiviral medications are being tested for the coronavirus, none are available yet.

Some researchers have also pointed to other potential differences between the two, with Lisa Maragakis from the John Hopkins Medical Centre highlighting the way in which they are transmitted:

“While both the flu and COVID-19 may be transmitted in similar ways, there is also a possible difference: COVID-19 might be spread through airborne transmission, meaning that tiny droplets remaining in the air could cause disease in others even after the ill person is no longer near.”

Is coronavirus more contagious than regular flu?

Because coronavirus is all over the news at the moment, it feels like it’s much more prolific than regular flu - but is that the case?

There are currently more than 190,000 cases of coronavirus confirmed across the globe.

Meanwhile, the CDC estimated that from 1 October 2019 to 29 February 2020 there were 34,000,000 – 49,000,000 of influenza in the United States alone.

That said, it’s not clear yet how the number of coronavirus cases will increase in the coming months.

The difference is that regular flu is something we are well used to dealing with, as Dr Anthony Fauci from America’s National Institute of Allergy and Infectious Diseases explained:

"I can tell you all, guaranteed, that as we get into March and April, the flu cases are going to go down. You could predict pretty accurately what the range of the mortality is and the hospitalizations" Fauci said. "The issue now is that there's a lot of unknowns."

On the other hand, there is no telling how things will proceed with the coronavirus because we have never faced it before.

At the moment, the CDC estimates that the rate of reproduction for the coronavirus is between 2 and 2.5, meaning that the average infected person will spread it to two or three people.

For seasonal flu, the rate is 1.3, so the coronavirus does appear to be significantly more contagious.

Is coronavirus more deadly than regular flu?

By the latest figures, there have been more than 190,000 confirmed cases of coronavirus, resulting in over 7,500 deaths.

As of 3 March, the World Health Organisation estimated that the virus carried a death rate of around 3.4% - meaning that roughly 3.4% of people who contracted the virus had died as a result.

However, because many people who contract the virus only display mild symptoms or no symptoms at all, it is possible that there are in fact many more cases than we know of, meaning that the apparent death rate is in fact an overestimate.

As a result, the WHO have warned that it is still too early to confidently judge the virus’ mortality rate.

A study carried out by the Chinese Centre for Disease control in February found that 13.8% of cases were considered ‘severe’ while 4.7% were labelled ‘critical’ – meaning they "exhibited respiratory failure, septic shock, and/or multiple organ dysfunction/failure.”

Even if the death rate is as low as 1% though, as some estimates have suggested, that would still make it about 10 times more deadly than the season flu which kills between 290,000 and 650,000 people each year according to the WHO.