Sus, you said:
"I became aware of this when I had my first child - because a lot of first time parents get paranoid about Autism, the characteristics and the correlation between immunisations and autism (however I have done extensive reading and there is NO (that's right - NO) scientific link between immunisations and autism."

You can't say that for sure. On Dr Briffa's site there was a very heated debated on this issue:
http://www.drbriffa.com/blog/2008/05/30/why-the-mmr-autism-war-is-not-over/

Also, if you don't want to immunise your kids you get a form from the Education Department I think, fill it out and kids can then go to school even when not immunised.

Both my kids are older and have already been immunised. If I had to make the decision now to immunise or not I would be very confused.