This sounds like Al*x J*nes fear mongering.

We got repeat calls from my son's school nurse about the lack of vaccinations. My wife said we don't believe in 'em... the nurse asked us to write a letter and sign it. It was a single line of handwritten text with her signature on a piece of copy paper. All good. No problems after that.

Bottom line: You don't need any form. Just a signed letter is all you need.

Try it. If it gets denied, then worry about it.