Hi, what did you end up deciding. I am not vaccinating DS and tetnus isn't something that I would just go out and get. I remember as a kid the only time I had one was when I had a cut from somethign rusty. I think if yoru kids were actually bitten or did cut themself 'then' go and get the shot. I dont' think you'd get tetnus right there and then, from memory going and getting the shot that day or next was OK. Feel free to correct me anyone as I dont' know the facts on this at all, just saying what my knowledge was from when I was a kid.