Immunizations & Immigration

United States Code 
TITLE 8 - ALIENS AND NATIONALITY 
CHAPTER 12 - IMMIGRATION AND NATIONALITY 
SUBCHAPTER II - IMMIGRATION 
PART II - ADMISSION QUALIFICATIONS FOR ALIENS; TRAVEL CONTROL OF CITIZENS
AND ALIENS

8 CFR 212.7

(2)25/ subsection (a)(1)(A)(ii) in the case of any alien- 

(A) who receives vaccination against the vaccine-preventable disease or diseases for which the alien has failed to present documentation of previous vaccination, 

(B) for whom a civil surgeon, medical officer, or panel physician (as those terms are defined by section 34.2 of title 42 of the Code of Federal Regulations) certifies according to such regulations as the Secretary of Health and Human Services may prescribe, that such vaccination would not be medically appropriate, or 

(C) under such circumstances as the Attorney General provides by regulation, with respect to whom the requirement of such a vaccination would be contrary to the alien's religious beliefs or moral convictions; or 


source:  http://www.ins.usdoj.gov/lpBin/lpext.dll/inserts/slb/slb-1/slb-21/slb-2264?f=templates&fn=document-frame.htm#slb-act212g