Abstract This phase 3 trial compared immunogenicity and safety of 2-dose versus 3-dose PF-06425090 Clostridioides difficile vaccine regimens in ≥50-year-olds (N=1994) at increased C difficile infection risk. Because TcdA but not TcdB immunogenicity noninferiority criteria were satisfied, the overall primary noninferiority objective was not met. Both regimens demonstrated similar safety profiles.
Crook et al. (Wed,) studied this question.