Virus / bacteria outbreaks have been common throughout history. They come quickly and often enough. About 3 or 4 come every 100 years. So you can expect one every 30 years.

Our last 4:

"Spanish Flu" in 1918-1919 "Asian Flu" in 1957-1958 "Hong Kong Flu" in 1968-1969 "Swine Flu" (H1N1) in 2009-2010

History teaches us to bet on viruses happening at anytime. Climate change deaths will be much slowier