As coronavirus disease (COVID-19) cases have been growing worldwide without any cure or vaccine still available, several theories about its origin are also circulating all over the internet. It is an infectious disease caused by a newly discovered coronavirus.
Let’s just break down each and every aspect of coronavirus to know more about the deadly disease. It has taken so many lives so far. People need to know its origin and how it affected people in the past. It will help them take it more seriously and take all preventive measures against the virus.
What is Coronavirus?
Coronaviruses are a family of hundreds of viruses that can cause fever, respiratory problems, and sometimes gastrointestinal symptoms too. The 2019 novel coronavirus is one of seven members of this family known to infect humans. In the past three decades, it has jumped from animals to humans.
The COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes. At this time, there are no specific vaccines or treatments for COVID-19. However, many ongoing clinical trials are evaluating potential treatments.
History of Coronavirus
Human coronaviruses, first characterized in the 1960s, are responsible for a substantial proportion of upper respiratory tract infections in children. Since 2003, at least five new human coronaviruses have been identified. It including the severe acute respiratory syndrome coronavirus, which caused significant morbidity and mortality.
The history of human coronaviruses began in 1965 when Tyrrell and Bynoe found that they could passage a virus named B814. It was found in human embryonic tracheal organ cultures obtained from the respiratory tract of a kid with a common cold.
The child had typical symptoms and signs of the common cold and the washing was found to be able to induce common colds in volunteers challenged intranasally. The virus, termed B814, could be cultivated in human embryo tracheal organ tissue but not in cell lines used at that time for growing other known etiologic agents of the common cold.
Within the same time frame, Almeida and Tyrrell found a similar virus in chickens. They performed electron microscopy on fluids from organ cultures infected with B814 and found particles that resembled the infectious bronchitis virus of chickens.
In the late 1960s, Tyrrell was leading a group of virologists working with the human strains and several animal viruses. These included infectious human bronchitis virus, mouse hepatitis virus and transmissible gastroenteritis virus of swine.
All of these had been demonstrated to be morphologically the same as seen through electron microscopy.
This new group of viruses was named coronavirus [corona denoting the crown-like appearance of the surface projections] and was later, officially accepted as a new genus of viruses. It was found that respiratory coronavirus infections occur more often in the winter and spring than in the summer and fall.
While the research was proceeding to explore the human coronaviruses, the number of animal coronaviruses were growing rapidly. It was found in many animals including rats, mice, chickens, turkeys, calves, dogs, cats, rabbits and pigs.
From where did the coronavirus emerge?
Given the enormous variety of animal coronaviruses, it was not surprising when the coronavirus respiratory infection called SARS emerged in 2002–2003 from southern China and spread throughout the world with quantifiable speed.
During the 2002–2003 outbreak, SARS coronavirus infection was reported in 29 countries in North America, South America, Europe, and Asia. Overall 8098 infected individuals were identified with 774 SARS-related fatalities.
It is still unclear how the virus entered the human population.
Since 2003, 5 new human coronaviruses have been discovered. Three of these are Group-I viruses that are closely related and likely represent the same viral species. In 2004, van der Hoek reported the discovery of a new human coronavirus, NL63, isolated from a 7-month-old girl with coryza, conjunctivitis, fever, and bronchiolitis.
The field of coronavirology has advanced significantly in recent years. The SARS epidemic was a dramatic reminder that animal coronaviruses are potential threats to the human population.
How coronavirus spreads?
Coronaviruses are divided into four groups called alpha, beta, gamma, and delta. These little invaders are zoonotic, meaning they can spread between animals and humans. Gamma and delta coronaviruses mostly infect birds, while alpha and beta mostly reside in mammals.
Mostly, if you got a coronavirus, you’d end up with a cold. But the most famous coronaviruses are the ones that jumped from animals to humans.
Coronaviruses are made up of one strip of RNA, and that genetic material is surrounded by a membrane studded with little spike proteins. When the virus gets into the body, those spike proteins attach to host cells, and the virus injects that RNA into the cell’s nucleus, hijacking the replication machinery there to make more viruses.
The severity of that infection depends on a couple of factors. One is what part of the body the virus tends to latch onto. Less serious types of coronavirus, like the ones that cause the common cold, tend to attach to cells higher up in the respiratory tracts, places like your nose or throat. But their more serious type attach in the lungs and bronchial tubes, causing more serious infections.
Coronavirus in 2019
According to preliminary estimates from the Centers for Disease Control and Prevention (CDC), the COVID-19 cases are hard to calculate because it keeps on increasing every passing day. The CDC calculates the death rate at about 2 percent.
The 2019 novel coronavirus disease [2019-nCoV or COVID-19] recently reported from Wuhan, China. The coronavirus grew from a few cases in Wuhan to become a pandemic in what seems like less than three months.
The first reports of cases of what would become COVID-19 came on December 31, 2019. Since then, more than 537,432 cases have been confirmed worldwide and the number is still rising, with more than 24,000 deaths. With new developments across the globe every day, it can be difficult to keep track of exactly what’s happening.
Bill Gates, Co-founder of Microsoft Corporation in his recent interview has said there is a spiritual purpose behind everything that happens.
About 35 companies and academic institutions are racing to create a vaccine for coronavirus. At least four of which already have candidates they have been testing in animals and humans.
Clinical trials usually take place in three phases. The first, involving a few dozen healthy volunteers, test the vaccine for safety, monitoring for adverse effects. The second, involving several hundred people, usually in a part of the world affected by the disease, look at how effective the vaccine is. The third does the same in several thousand people.
There is another potential problem. As soon as a vaccine is approved, it’s going to be needed in vast quantities. However, the vaccination might still take at least 6-8 months to come to the public.
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