Human Corona Viruses
In humans, the virus causes respiratory infections, which are often mild, but in rare cases are potentially lethal. There are no vaccines or antiviral drugs that are approved for prevention or treatment.
Most coronaviruses are not dangerous. Almost everyone gets a coronavirus infection at least once in their life, most likely as a young child.
There are seven known strains of human coronaviruses.
Common human coronaviruses, including types 229E, NL63, OC43, and HKU1, usually cause mild to moderate upper-respiratory tract illnesses, like the common cold. Human coronaviruses can sometimes cause lower-respiratory tract illnesses, such as pneumonia or bronchitis. This is more common in people with cardiopulmonary disease, people with weakened immune systems, infants, and older adults.
Two other human coronaviruses, MERS-CoV and SARS-CoV have been known to frequently cause severe symptoms. MERS symptoms usually include fever, cough, and shortness of breath which often progress to pneumonia. About 3 or 4 out of every 10 patients reported with MERS have died.
In early January 2020, the World Health Organization identified a new type: 2019 novel coronavirus (2019-nCoV) in China. Hundreds of patients have been infected with the virus across China, with central Hubei province the worst-affected.
Symptoms of China Corona Virus