Got a cite for that "seven years" figure?

According to this web page, lots of vaccines last more than 7 years, with some lasting for life:

http://www.traveldoctor.co.nz/vaccinations.aspx

Of those that don't last for life, adults do get booster shots. I don't know why you think they don't. I get a flu shot every year and I get boosters for other diseases every so often when I have a physical.

I don't immunize my child because she's marginalized and powerless to resist. I do it because it's a cheap, easy, and safe way to reduce her chances of discomfort, disability, and death. Her mother and I often try to get our vaccinations at the same time she does so we can show her that she's not alone.