I have heard that you still get it if you choose not to vaccinate as long as you have put in a contentious objectors form through your dr. But havent confirmed that with centrelink

yup, it pays automatically if you have conscientious objection form lodged, or if your child is behind due to illness and your Dr lodges a catch up plan

the 18 month needle isn't compulsory either - when the MIA started, it was, but isn't anymore in some states, so they give you til 18 months to have your kidlet up to date with 12 month injections