They add that many more mutations would probably be necessary before the virus is capable of sparking a full-blown pandemic, in which disease spreads like wild fire from person to person.

• 他们还表示：病毒很可能需要比这多得多的变异，然后才能引发全面爆发的传染病，如果发生这种情况，疾病将象野火一样在人间蔓延。