Coronaviruses are a large group of viruses that are common among animals. In rare cases, they are what scientists call zoonotic, meaning they can be transmitted from animals to humans, according to the US Centers for Disease Control and Prevention. It is a dangerous diseases with incubation period between 4-6 days. It is fatal especially for those with weakened immune system, the elderly and the very young. It could also result in Pneumonia and bronchitis.