{HEAD ~ These vaccines} are produced with {TAIL ~ portions} of C. difficile Toxin A, or Toxin B, or both 
are produced with
{ HEAD ~ These vaccines } are produced with { TAIL ~ portions } of C. difficile Toxin A , or Toxin B , or both
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH