What are the symptoms of coronavirus infection?

Coronaviruses can cause respiratory and digestive diseases. They also contribute to epidemics that occur among mammals and birds every few years. The first viruses of this type were detected in the middle of the 20th century, but they only caused mild diseases. However, the first deadly crown-viruses were discovered in China in 2002 (SARS) and the next – also deadly to humans and animals – at the end of 2019 (also in China). Some say that in both cases the virus was released from the laboratories where the research was carried out. Is this really true? Read more