The fact that your son has not been vaccinated is a problem no matter whether it's family he's visiting or not. Many people in public places could pass diseases on to him that could kill him.
Your local health department will provide vaccinations free of charge if you cannot afford a regular pediatrician.
If your son remains unvaccinated, it will be impossible to enroll him in daycare, elementary school and team sports.
I hope that you will look further into this soon.

