My 5 yr old son has never been vaccinated other than what was given at birth, yet he's never been sick other than an occassional cold. is this safe?

Well...: You and him are walking a fine line. The fact he's been healthy may stem out of the fact that he's been around children/folks who are vaccinated, so the prevalence/incidence of a particular disease is small in that community. If he were to happen to be in a situation where there are a lot of unvaccinated folks like him, he may contract a potentially preventable disease and only god knows outcome.

Not recommended : Vaccines are extremely safe where the benefits far out weight the risks of vaccination. It would be devastating to lose a child from a preventable illness just because a vaccine was not given. Nonetheless, oat physicians will also respect the personal convictions of their patients (as long as the risks and benefits have been fully explained to you.).