You have probably heard that the authorities, with their warnings about coronavirus, go too far, and that the virus can be compared to the usual seasonal flu. This is not true. In almost all respects, the new coronavirus is much more dangerous than the flu. This is written by the Danish publication Videnskab.
The article draws attention to the differences between influenza and the new viral disease COVID-19.
Coronavirus is more contagious
Coronavirus, like flu, is transmitted by airborne droplets. But he’s twice as contagious. A person with the flu infects an average of 1.1 more people. That is, its reproduction rate is 1.1.
The new coronavirus has a reproduction rate of 2.5. This is evidenced by studies conducted in the Chinese province of Hubei, from where the virus spread. This means that an average person infected with coronavirus infects another 2.5 people.
“The reason why coronavirus is twice as infectious as the flu is probably because none of us have immunity to it, because it’s a new virus, and no one has had this disease before,” explained a professor at the Institute of Public Health at Aarhus University (Denmark) Christian Weiss.
Other coronavirus particles
Also, the high infectivity of the coronavirus can be associated with the method of its penetration into the body. Typically, a person becomes infected with a virus transmitted by airborne droplets by inhaling pathogenic particles.
Immunity copes with some particles even before they manage to penetrate deep into the body. It seems that immunity fights against particles of coronavirus and influenza virus with varying effectiveness, says a professor of immunology at the University of Copenhagen Jan Pravsgor Christensen.
“It’s possible that fewer particles of coronavirus are needed to cause the disease than particles of the flu virus,” he says.
More people die from coronavirus
According to scientists, mortality from the new coronavirus is about six times higher than from ordinary seasonal flu.
“That’s why we are alarmed,” Weiss points out.
The numbers are still inaccurate, but according to average estimates, mortality from coronavirus is 0.6%. About 0.1% of those infected die from normal seasonal flu.
Inaccurate data
The exact mortality from COVID-19 is still unknown, because different countries calculate the number of infected people in different ways.
In countries where not many people check for coronavirus, there are very few reported cases. Therefore, it may seem that there are more deaths from a new disease than in countries where more extensive checks are carried out and patients are registered more thoroughly.
“In the United States, mortality from it is now 3.5%, because few have been tested there. And in South Korea, where a lot of people were examined, the mortality rate is at the level of 0.6%, ”says Weiss.
In Italy, mortality has now reached 6.2%. According to the scientist, this may also be due to the fact that the outbreak of the disease hit the country so hard that its health system no longer keeps up with the development of events and can not examine everyone. In addition, a very significant proportion of the Italian population are older people who are more at risk of dying from coronavirus than young people. More than two million Italians are over 85 years old, and life expectancy in Italy is one of the highest in Europe.
More people get seriously ill
Every year, thousands of Danes get the flu. Elderly people and people with poor health are particularly at risk of getting into the hospital. In the flu season 2017–2018, 971 people were hospitalized with him. Of these, 50 were seriously ill and were in intensive care, according to the Danish State Serum Institute.
The new coronavirus seems to be much more severe.
“In Hubei, 3–5% of those infected were in intensive care. If everything goes as bad in Denmark, we will have a collapse of the healthcare system, as in Italy, ”emphasizes Christian Weiss.
The Department of Health conducted a risk assessment and stated that approximately 600,000 Danes could be infected with the coronavirus. If we apply the data from Hubei to this figure, it turns out that 4% of these 600 thousand people can get into intensive care. And this is 24 thousand people.
However, it is unlikely that everything will be so bad. The Department of Health believes that 2.8 thousand Danes with coronavirus will receive resuscitation in the next three months.
Coronavirus infects the lungs
Influenza virus consists of pathogenic particles that settle on receptors in the nose, mouth and throat. Coronavirus most often affects lung receptors.
“This means that the virus multiplies at the bottom – in the lungs, while the flu – in the upper respiratory tract. Thus, coronavirus is pneumonia that affects respiration and the ability of the lungs to saturate the blood with oxygen. This is probably why they die from him more often than from the flu, ”the professor believes.
In particularly unlucky patients, coronavirus appears as a very severe form of pneumonia.
Influenza and coronavirus may look similar.
However, most people do not get sick so much, and although the coronavirus and influenza virus affect different organs, their symptoms often coincide, making them difficult to distinguish.
“These two diseases often manifest the same way,” emphasizes Jan Pravsgor. – 80% of those infected with coronavirus experience only minor symptoms of a cold. Therefore, people continue to work and infect others before they discover that they have a coronavirus. ”
When older and weak people get the flu, they can also have a complication of pneumonia. But, unlike coronavirus, it is not the virus itself that causes such pneumonia.
“When a person has the flu, his lungs may suffer, and bacteria will open up. But with flu, pneumonia is usually only a secondary effect, ”added Jan Pravsgor.
No one has immunity against COVID-19
Viral diseases are characterized by the fact that, having been ill once, a person gains immunity. This means that we rarely get the same virus twice. After many are ill with a disease, collective immunity is formed.
“The more people who get sick, the more difficult it is for the virus to spread,” Christensen explains.
Every year, various variants of coronavirus, like flu viruses, cause a cold in us. But the new coronavirus is not like most coronaviruses known before.
“The disease that affects people now is so different from the rest that no one has immunity against it. This virus is new for everyone, ”the scientist explained.
When no one has immunity, the virus spreads at lightning speed.
Many have flu immunity
Immunity is formed when the body’s defense system recognizes molecules on the surface of the virus and produces antibodies against them that destroy the particles of the virus, preventing the person from getting sick.
You must have heard that the flu viruses mutate, and every year a new option appears. But, although viruses mutate, different versions of seasonal flu are not so different from each other that the immune system could not recognize them. Therefore, most of us are much better protected from the flu virus than from the new coronavirus.
“Most people have the flu at least once in their life, so the population always has some basic immunity,” notes Christensen.
Human immunity “forgets” colds
If you have had childhood illnesses like measles or chickenpox, you will have immunity for the rest of your life. But immunity to colds in humans is not formed.
“Cold viruses do not“ remember ”immunity so well, just like the coronavirus variants that we already know. Immunity will respond to them for a maximum of four to five years. Whether this is the case with the new coronavirus, I do not know. It will take several years to understand how stable immunity is formed, ”the professor concludes.
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