do not die, . . .or survive deaf, blind, brain-damaged or heart-damaged. Go on Rich Reader, take one for the team in a community spirited way: you have nothing to lose but your firstborn.
In the back of my 'mind' I've always know that the epidemiology of vaccination is different for each pathogen. Some diseases are really difficult to catch (Leprosy) while others propagate easily (chicken
pox). Then I came across this really handy document written by Patrick Honner a New York high-school teacher and jobbing quant. It explains the maths of herd immunity. You should read it.
The point Honner makes is that we'll all be fine if each infected person transmits the lurgy to one other person: that's linear growth. If each one infects 2 other people, you have exponential growth because those two pass it to 4 those four to 8 and after 10 rounds of replication you have 1024 people down sick - a kilobug you might call it. If we can interrupt or slow down the propagation to one-a-time after ten rounds only 10 people have been affected. There are two aspects of the life-cycle of the pathogen that are relevant 1) how easy it is to catch and b) how long is the infectious period. These can be conflated into a single statistic the 'basic reproductive ratio' R0 which varies for each disease. Measles [tiny case shown R above] is usually reported as top of the list:
If you're a teacher this worksheet may be useful.