[Pants]

Originally Posted by 'Hamas' Jenkins

It's a bit complicated. Here's the best explanation I can offer:

If everyone gets a vaccine that is highly efficacious and protection is long-lasting, then the disease has no reservoir and it dies out. This is what happened to smallpox, even though it wasn't 100% effective.

However, let's say that there isn't universal vaccination. The disease has a small reservoir of potential people to infect and it dies out, right? Well, not always, because the antivaxxers are constantly replenishing the pool of the unvaccinated, and with each person it infects, the odds of a mutation that renders the vaccine less effective for the inoculated population increases, and vaccine efficacy can wane over time, which is why we have boosters for certain vaccines like TDaP.

One MMR vaccine is a little under 80% effective in protecting against mumps, two a little under 90%. This would normally be more than enough to protect, but if you have a pool of people that won't get the vaccine, that is enough to cause these small outbreaks amongst the vaccinated-but-still-vulnerable population.

This is why to stamp out COVID we will need near universal vaccination rates. As long as there isn't a mutation in the spike protein the underlying mechanism behind the vaccine should be fairly durable (I'm a bit out over my skis on this one), but boosters will likely be offered and become relatively commonplace, although I'm unsure of their frequency.

That totally makes sense. Thanks, man.