David P wrote
Brian Gaff wrote

I thought is was because there are enough people
not vaccinated for a reservoir to exist to re infect.

That is why there is a critical number or percentage
and why the bad press of the multiple vaccination
system harmed the program.

What happens to any other species when
their numbers keep rising, without controls?

Human populations work differently. There is a reason why
we no longer see many with more than a couple of kids in
the modern first world. In fact NOT ONE modern first world
country is even self replacing now if you take out immigration.

What will the world be like as our population increases to 8 billion,
then 9 billion, then 10 then 11 billion, as the United Nations projects?

Basically the same as it is now, with the
bigger citys just being bigger in total area.

We need to discuss decisions based on self
vs. decisions based on the common good.

Nope, the birth rate is dropping EVERYWHERE now
except where its already right down in the noise.
https://en.wikipedia.org/wiki/List_o...#1970_and_2014

Its fixing itself fine.

(the common good includes other creatures and future generations).

"David P" wrote:
Scientists Thought They Had Measles Cornered. They Were Wrong.
Following intensive vaccination efforts, measles cases plunged across the
world. Now clusters of new infections - some linked, some not - have
confounded health officials.
By Donald G. McNeil Jr., April 3, 2019, NY Times
[...]