"For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places." (Matthew 24:7)
"And great earthquakes shall be in divers places, and famines, and pestilences; and fearful sights and great signs shall there be from heaven. (Luke 21:11)
These pestilences are unique, new, mysteriuos and resistant, that's why Jesus mentioned them as a sign of His coming!