Coronaviruses are a large and diverse viral family. They have a wide host range, including humans.
Coronaviruses cause both COVID-19 and SARS. SARS-CoV is the virus that causes SARS, whereas COVID-19 is caused by SARS-CoV-2.
Human coronaviruses typically cause mild respiratory infections such as the common cold. Human coronaviruses account for 10 to 30% of upper respiratory tract infections in adult individuals. >R<
SARS is the name given to the respiratory sickness caused by SARS-CoV. SARS is an abbreviation for severe acute respiratory syndrome.
It was discovered for the first time in 2003.
From late 2002 to mid-2003, there was a worldwide SARS outbreak. During this time, almost 8,000 people became infected with the virus, and 774 died. >R<
One of the initial indications of SARS is fever. Other symptoms may accompany this, such as: cough, malaise, or exhaustion; aches and pains in the body;
shortness of breath and headaches.
Respiratory symptoms can deteriorate, resulting in serious symptoms advancing quickly, leading to pneumonia or respiratory failure.
COVID-19 and SARS are comparable in many aspects.
Both are coronavirus-caused respiratory illnesses that are transmitted by respiratory droplets produced when a person with the virus coughs or sneezes.
The transmission can also occur through contact with objects or surfaces containing the virus. >R<
Both infections can lead to potentially serious illness, sometimes requiring oxygen or mechanical ventilation can have worsening symptoms later in the illness.
Both of these coronaviruses have similar at-risk populations, including older persons and those with pre-existing medical issues.
The novel coronavirus also shares 79 percent of its genomic sequence with the SARS virus. >R<
Although SARS-CoV-2 is more closely related to bat coronaviruses in general, the receptor binding site is more comparable to SARS-CoV.
SARS-CoV-2 and SARS-CoV use the same host cell receptor, according to a new study. It was also shown that the viral proteins needed for host cell entrance attach to the receptor with the same tenacity in both viruses – they have similar affinity. >R<
Despite these similarities, there are also some significant distinctions between the two:
SARS cases were often more severe. It is estimated that 20 to 30 percent of people with SARS needed respiratory support and ventilation. >R<
The fatality rate of SARS is higher than that of COVID 19.
The expected mortality rate is around 10%, with mortality rates as high as 45% in particular patient populations. >R<
SARS-CoV-2 seems to be more easily transferred than SARS-CoV.
One theory is that the volume of viral load is greatest in the nose and throat of patients who have COVID-19 immediately after symptoms emerge.
With contrast, in SARS, virus loads peaked relatively late in the infection.
People infected with COVID-19 seem to shed the virus earlier than people infected with SARS, although there haven’t been any confirmed cases of SARS CoV transmission prior to the onset of symptoms.
In another study, researchers compared the part of the viral protein that binds to the host cell receptor. The study also discovered that SARS-CoV-2 has a receptor binding site that binds to the host cell receptor more strongly than SARS-CoV. >R<
On the point of cross immunity to SARS CoV-2 because of an earlier acquired immunity to other coronaviruses, previous studies have found that about 40–50% of the population has cross-reactive T-cells, most likely as a result of another coronavirus exposure in the past.
According to German research, even if COVID-19 patients did not produce antibodies, the majority of them elicited a T-cell response.
The study also discovered that T-cells from previous coronavirus exposure cross-reacted with SARS-CoV2 in about 80% of the control group (patients without COVID-19). Although this cross-reactivity may not provide complete immunity for everyone, it may help to alleviate symptoms. >R<