To date, no immunologic correlate of protection has been established
for S. aureus infection. Previous studies of immunogenic
S. aureus vaccines have failed to produce efficacious results in later
pivotal studies (19) (S. Deresinski, presented at the 12th International
Symposium on Staphylococci and Staphylococcal Infections,
Cairns, Australia, 7 to 10 September 2008). An eventdriven
phase IIb/III efficacy trial of V710 in patients
undergoing cardiothoracic surgery (ClinicalTrials.gov registration
number NCT00518687) was recently terminated after
the second planned interim analysis because of potential safety
concerns as well as low vaccine efficacy closely approaching the
protocol-stipulated futility threshold of 20% (5) in spite of
brisk antibody responses in V710 recipients.