In humans, coronaviruses typically cause a respiratory infection with mild to severe flu-like symptoms, but the exact symptoms vary depending on the type of coronavirus.
The four common human coronaviruses can cause people to develop a runny nose, headache, cough, sore throat and fever, according to the CDC. In a subset of individuals, including those with cardiopulmonary disease or a weakened immune system, the viral infection can progress to a more severe lower-respiratory infection such as pneumonia or bronchitis.
In comparison, severe MERS and SARS infections often progress to pneumonia. Other symptoms of MERS include fever, coughing and shortness of breath, while SARS can cause fever, chills and body aches. SARS had a mortality rate of 9.6% in the early 2000s outbreaks, according to The New York Times, while MERS has an estimated mortality rate between 30% and 40%, the CDC noted.
The novel coronavirus causes symptoms similar to those of other coronaviruses, triggering fever, cough and difficulty breathing in most patients. Rarer symptoms include dizziness, nausea, vomiting and a runny nose. As of February 2019, scientists estimate the 2019-nCoV mortality rate at 2%, although that figure may be somewhat skewed by the severity of the cases studied so far. As more mild cases of the infection are accounted for, the estimated mortality rate may fall.