FYI Yellow fever certificates

I know this gets asked a lot, but on returning to Australia this morning, they asked to see my yellow fever certificate, because I had visited Bolivia. Now I know Australian customs and quarantine are some of the toughest in the world, but just so people are aware, your home country may want to see it. Apparently if i didn't have the certificate, I'd have to go have tests and pay for them.

I've been asked for it a couple of times..Panama was one place i remember that they wanted to see it (after finding various South American stamps in my passport).

#1, a lot of people seem to think its ok to not be vaccinated for it. There is a reason the WHO are trying to restrict this and its the only vaccination that has an offical certificate AFAIK.