We've now had the first cases in Australia, among people who have recently returned from the UK. I heard an infectious diseases academic on the radio this afternoon say that it's not as contagious as smallpox, and that transmission has historically been unusual but not unknown between humans, and more common as direct transmission from an infected animal. She said that smallpox vaccinations are protective, as previous posters have noted, and also that there are smallpox anti-virals that are protective. We never had community vaccination programs against it here so perhaps 10% of the population has been vaccinated, me amongst them for travel in the 1970s.