Miao-lo said, "Wise men can perceive the cause of things, as snakes know the way of snakes." The present epidemics are like the virulent boils of King Ajatashatru that could not be cured by anyone but the Buddha. They can only be eliminated by the Lotus Sutra.

The Writings of Nichiren Daishonin, page 920
The Two Kinds of Illness
Written to Shijo Kingo on June 26, 1278