WHAT ARE RELIGIOUS EXEMPTIONS TO THE FLU VACCINE?

I live in New Jersey & have a 3 year old who will be entering preschool, what are religious/medical exemptions to the flu vaccine? I strongly disagree with the state mandate. Anyone have any idea of when is the deadline to get the flu vacine for your child.Some sites state dec 31st but am not sure if that has changed.any help will be appreciated.Thanks!