Does my unvaxinated child need a Tetanus shot? please help?

Patient: My 3 year old son has only had his first 2 lots of vaccinations, after the second lot he ended up in hospital inconsolable and screaming in pain for the entire night. We decided then that we would not vaccinate him again. 3 days ago he pulled a wheel off a toy car that was in the shower and put it outside on our pavement (not anywhere near soil) he went out side and stepped on the nail part that was sticking out which was roughly 1cm long. There was no blood and was on the hard part of the bottom of his foot. Ime not sure how far it went in but doesnt appear to be deep. However we are now worried he may have tetanus. We are very worried that if we take him to the doctors and get the vaccine he may react to it again, especially as his immune system is low after just being on a course of antibiotics but we are also stressing out and loosing sleep worried that he might have Tetanus. We live in Western Australia.

Symptoms: None