On that FB thread, one commenter proudly proclaimed that she & her four children had all had measles. Over in a week, no problems, stop yer whining.
Well, lovely for her - & if the illness indeed lasted only a week per person then they were lucky; 7-10 days is the norm for uncomplicated measles. But measles infection carries a range of costs & risks, about which she seemed blissfully ignorant. Or couldn't care less; on that thread, it was hard to tell sometimes.
If a child comes down with measles, someone has to stay home (or pay someone else to stay home) & care for them, for a week or more. For many families, that's quite a financial burden.
If any individual comes down with measles, there's a taxpayer cost, because their contacts need to be traced, checked, asked to quarantine themselves if infected.
If that individual develops any of the severe complications of measles (& the risks of that are much greater than the risks associated with vaccination) then the costs to families (in terms of disruption, travel to hospital, time off work) & to the taxpayer (hospitalisation & medications) climb again. (The figures at that link are from the US, but the message is the same.)
After recovery, anyone who's been ill with measles is at risk of succumbing to other infections. This is because measles infection reduces the immune system's ability to fight off other pathogens for up to three years.
And in rare cases, especially if they contracted measles as an infant, that individual may develop the progressive brain inflammation known as subacute sclerosing panencephalitis. There is no cure and it is often fatal.
The vaccine is a better option. Seriously.