New Jersey Statutes Title 26. Health and Vital Statistics 26 § 2N-9

a. Prior to administering a second dose of the measles-mumps-rubella (MMR) vaccine to a child, a health care provider may give the child's parent or guardian the option of consenting to the administration of an antibody titer to determine whether or not the child has already developed immunity to MMR in response to a previously administered dose of the vaccine and would not require the second dose.

b. Documented laboratory evidence of immunity from MMR shall exempt a child from further vaccination for MMR, as may be required pursuant to Department of Health regulations.