Another crucial feature that made SARS-1 easier to control than SARS-2 is that it was generally not transmissible before a patient was symptomatic. That was why a large percentage of SARS-1 infections showed up in medical professionals—they were exposed to SARS-1 patients who were already quite sick. It was precisely when these patients went to the hospital, often near death, that they were most infectious. But SARS-2 is transmissible before symptoms show up.
