Variable, but my auto-immune bullshit means that my immune system usually goes apeshit when I prod it with a stick. One year I had no reaction and Jason did, though, which was weird.

We *do* have a shortage here - I had an appointment a month ago to get it done at the pharmacy but they couldn't get doses so I've had to go through my GP (I'm entitled to a free one because of my asthma) which has meant a month's wait and a less convenient appointment).