I am very firmly in the pro-vaccine camp, and that's even after someone in my wife's family was affected negatively by them, because I know about how many more kids suffered (and died) due to preventable childhood diseases.
So my thoughts on having children tend towards the very old-fashioned, in a sense. Generally speaking, and at the risk of accidentally offending someone here: I don't get along too well with the sort of person who doesn't like kids. I understand many people have good reasons not to have children of their own: health risks, other life commitments, infertility, etc. But the sort of person who says "I never want crotchspawn because of what it'll do to my body or because I can't travel or because I just don't like kids" always rubs me the wrong way.
This has nothing to do whatsoever with gay and straight, obviously. Many of my gay friends, and my sister (who is in a same-sex marriage) love children. Some of them adopt, some of them have children from a prior relationship, or have kids through various other arrangements. Even those who never have their own frequently turn out to be awesome uncles and aunts or godparents, and that's cool in my book too.
Loving children is a part of being human, and a part I'd never want to see us give up as a species.
Personally (and I understand this won't hold true for everyone), becoming a father has made me a better man in virtually every way. I've never worked as hard, never despaired as much -- and I've never had as much fun or as much satisfaction. And mine are still small!