Hassanzadeh H, Baber J, Begier E, Noriega DC, Konishi H, Yato Y, Wang MY, Le Huec JC, Patel V, Varga P, Liljenqvist U, Conly J, Sabharwal C, Munjal I, Cooper D, Radley D, Jaques A, Patton M, Gruber WC, Jansen KU, Anderson AS, and Gurtman A
Background: Staphylococcus aureus is a global pathogen that is frequently responsible for healthcare-associated infections, including surgical site infections (SSIs). Current infection prevention and control approaches may be limited, with S. aureus antibiotic resistance remaining problematic. Thus, a vaccine to prevent or reduce S. aureus infection is critically needed. We evaluated the efficacy and safety of an investigational 4-antigen S. aureus vaccine (SA4Ag) in adults undergoing elective open posterior spinal fusion procedures with multilevel instrumentation., Methods: In this multicenter, site-level, randomized, double-blind trial, patients aged 18-85 years received a single dose of SA4Ag or placebo 10-60 days before surgery. SA4Ag efficacy in preventing postoperative S. aureus bloodstream infection and/or deep incisional or organ/space SSIs was the primary end point. Safety evaluations included local reactions, systemic events, and adverse events (AEs). Immunogenicity and colonization were assessed., Results: Study enrollment was halted when a prespecified interim efficacy analysis met predefined futility criteria. SA4Ag showed no efficacy (0.0%) in preventing postoperative S. aureus infection (14 cases in each group through postoperative day 90), despite inducing robust functional immune responses to each antigen compared with placebo. Colonization rates across groups were similar through postoperative day 180. Local reactions and systemic events were mostly mild or moderate in severity, with AEs reported at similar frequencies across groups., Conclusions: In patients undergoing elective spinal fusion surgical procedures, SA4Ag was safe and well tolerated but, despite eliciting substantial antibody responses that blocked key S. aureus virulence mechanisms, was not efficacious in preventing S. aureus infection. Clinical Trials Registration. NCT02388165., Competing Interests: Potential conflicts of interest. H. H. is a consultant for Medtronic, DePuy, Nuvasive, and Orthofix; has obtained research support from Orthofix, Nuvasive, Medtronic, SKK, and Pfizer; has taught/spoken for Nuvasive, Medtronic, Orthofix, and Globus; has received payment for expert testimony from the Expert Institute; has participated on an advisory board for MTF; and reports stock or stock options with Nuvasive and 4Web. V. P. is a consultant for Medtronic; has obtained research support from Pfizer, Orthofix, Medicrea, Mainstay Medical, SI Bone, and Premia Spine; reports grants or contracts from Spinal Kinetics; reports consulting fees from DePuy Synthes, J&J SI-BONE, Mainstay Medical, Zimmer, Baxter, Stryker, and Aesculap; has filed multiple patents with the university office; and receives royalties from Stryker and Aesculap. H. K. has served as a consultant for Pfizer. D. N. is a consultant for Stryker. J. B., E. B., C. S., I. M., D. C., D. R., A. J., M. P., W. C. G., K. U. J., A. S. A., and A. G. are current employees of Pfizer and may hold stock or stock options. A. J. reports support for attending meetings as part of duties as a Pfizer employee and STRIVE team member. J. C. reports grants or contracts from the Canadian Institutes for Health Research and from Alberta Innovates; has received accommodations and airfare to attend and speak at a symposium from bioMerieux Canada; and is a member and chair of the World Health Organization (WHO) and a member of the WHO Health Emergencies Programme Ad-hoc COVID-19 IPC Guidance Development Group, both of which provide multidisciplinary advice to the WHO, for which no funding is received and from which no funding recommendations are made for any WHO contracts or grants; and works as an infectious diseases consultant at Alberta Health Services. K. J. reports consulting fees from and patents with Pfizer. M. W. reports royalties or licenses from Depuy-Synthes Spine; consulting fees from Depuy-Synthes Spine, Pacira, Stryker, NuVasive, Spineology, and Surgalign; and stock or stock options from Innovasive Surgical Devices, Kinesiomerics, and Medical Device Partners. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)