A friend spent much of 2018 and 2019 in China in intermittent stretches 1 to 2 months in length. In early 2019 he contracted a form of pneumonia, with coughing and bloody sputem. After returning to the United States, he slowly recovered. His doctors were stumped as to what caused his infection. He is mostly recovered now, with occasional respiratory issues; but was struck by the similarity to the symptoms he experienced and what is being reported as the symptoms for the coronavirus. He's wondering if the infection he experienced, was simply a less virulent version of the coronavirus that has now mutated into a more highly infectious form. Is there any value in him getting tested with the coronavirus test kit? If he tests positive, would the antibodies his body developed since the infection be of any value or interest to doctors studying this outbreak?