In this article we will find out the current science which is working behind this deadly virus. How this virus has taken so many lives and also its types. How it enters the human body and its common symptoms.
In 90% of people tested positive for covid-19 antibodies, the researchers found, there was an enormous level of neutralizing antibodies. The antibodies were the most important in preventing a second infection. The presence of these neutralizing antibodies remained stable at least three months post-recovery.
Neutralizing antibodies are often a key indicator of immunity. So this is a good sign that covid-19 immunity for most people should last for at least the near future. Other research also show that a second form of immune response, led by T cells, is robust. Following a bout of covid-19. But we still have to be vigilant and track survivors to know if and when immunity may start to wane.
Let us first know the origin of this deadly virus:
Coronaviruses (CoVs) are a family of viruses that cause respiratory and intestinal illnesses in humans and animals. They usually cause mild colds in people but the emergence of the severe acute respiratory syndrome (SARS) epidemic in China in 2002–2003 and the Middle East respiratory syndrome (MERS) on the Arabian Peninsula in 2012 show they can also cause severe disease.
In December 2019, a cluster of patients suffering from an atypical pneumonia was reported in Wuhan city, Hubei province, China. Although the precise origins of this disease outbreak remain unknown, several of the early COVID-19 patients could be linked to a live animal market. During an outbreak of a disease that jumped from animals to humans (a so-called zoonotic disease), identifying the source of infection can allow health authorities to protect people by separating them from the animals posing an infection risk.
The genome sequence of the virus causing atypical pneumonia in Wuhan was made available to the research community in early January 2020. It was quickly identified as a coronavirus similar to the virus that caused the 2003 SARS outbreak, which also began in China. The new coronavirus was given the formal name SARS-CoV-2 and is the cause of the disease called COVID-19. The hypothesis that COVID-19 was a zoonotic disease like MERS (Middle East respiratory syndrome) and SARS (severe acute respiratory syndrome) was supported by the observation that many of the early cases were associated with a “wet” food market in Wuhan where numerous live animals of different species were kept prior to sale.
After the emergence of SARS and MERS (and other zoonotic diseases) there were calls for restrictions on wildlife consumption by humans and the sale of wild animals in live markets. These recommendations are being restated during the current COVID-19 pandemic; whether they are justified on these grounds depends on knowing the animal origin of SARS-CoV-2 and how it entered the human population.
Here is the types of coronavirus newly found:
To date seven human coronaviruses (HCoVs) have been identified (see table below). Four of them are common; less high risk and typically cause only mild respiratory illnesses in healthy human adults. However, they contribute to a third of common cold infections and, in higher risk people with weak immune systems, they can cause long term, life-threatening illnesses.
Human corona viruses are:
Because this virus is new, no-one has any immunity to it. This means it will potentially infect very large numbers of people. And even though the number of very severe cases is low in percentage terms, a small percentage of a very large number adds up to many people with acute illness.
How this virus enters the human body?
Coronaviruses enter the human body by being inhaled or via direct touch to the mouth, nose and eyes. They bind to and infect the cells lining the upper and lower airways and lungs. On average, symptoms will develop five days after infection, but this can range from two to 12 days. The time between infection and symptoms developing is called the incubation period. In an unknown number of people, the infection may resolve itself without the individual experiencing any symptoms at all. This is probably due to a fast and effective response by the immune system.
Symptoms generally occur after the virus causes direct damage to the cells of the airways and lung, or when the virus triggers an immune response. Irritation of the airway produces a sore throat and cough and sometimes a blocked or runny nose. A cough is a reflex to clear the airway of perceived phlegm, though COVID-19 usually produces a dry cough.
Pneumonia: n COVID-19 pneumonia usually appears in patches in the lower parts or outer edges of both lungs. Even in people without symptoms, pneumonia sometimes shows up on CT scans. In most cases of COVID-19, the pneumonia resolves completely, often without serious illness.
Acute respiratory distress syndrome (ARDS): ARDS is usually detected because the individual becomes severely unwell over just a few hours. Doctors can use a chest X-ray or scan to identify ARDS because they often show changes that are distinct from those caused by pneumonia.
Injury to the heart: In critical illness with COVID-19, the heart can be affected too. In the worst cases of this infection, the heart may be damaged but it is not yet known whether this is due to direct effects of the virus or to the body’s response to the presence of virus in the lungs.