At this time, scientists cannot be certain exactly when the next pandemic will occur, and whether it will rival the experience of the 1918-19 pandemic or be more muted like in 1957-58 and 1968-69.

• 目前科学家无法完全肯定下次大流行何时爆发，以及是否与1918-1919大流行一样严重，还是比1957-1958和1968-1969的流感危害轻。