Experts conjecture that the amount of the virus one is initially exposed to seems the most significant factor. But because the SARS virus mutates frequently, is it possible that some viruses just become more severe, more virulent the more they mutate?
專家推測，最初吸入病毒「量」的多寡，似乎是最重要因素，但因為 SARS 病毒變異多端，會不會有些病毒湊巧越變越狠、越變越毒？