Obesity is in itself a sickness in many cases. I think the implication that people "do it to themselves" really ignores the large pile of evidence that shows that it's really difficult to treat it effectively. Similarly other examples such as alcoholism or other substance addiction suffer from the same issue.
When it comes to vaccine hesitation I am not sure where to draw the line. It's a very emotional topic apparently and it seems rational arguments only go so far.
That said, I think if a society only treats those medical emergencies deemed to have a "non-egoistical" cause Pandora's box will come to haunt us sooner or later. We should save humans whenever we can. That's just the cost of doing business so to speak.
