ABSTRACT
N.M., RSV, Janssen Infectious Diseases, Infection
CLINICAL INFECTION, INFECTION
Present address: TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, GermanyPresent address: Amicus Therapeutics, Philadelphia, Pennsylvania, USAPresent address: Moderna, Cambridge, Massachusetts, USAY.C.B., D.C., D.Y., and N.M. have nothing to disclose. J.T., R.v.H., J.S., C.A.C., E.H., B.C., and A.R.B. are employees of Janssen Vaccines & Prevention B.V. E.D.P. is an employee of Janssen Infectious Diseases. G.A. is a current employee of Moderna, received research grants from the Massachusetts Consortium on Pathogen Readiness, received consulting fees from Sanofi Pasteur for participation on a scientific advisory board, and owns stock or stock options in SeromYx Systems, Inc., and Leyden Labs.An Ad26.RSV.preF/RSV preF protein combination vaccine demonstrated 80.0% vaccine efficacy for the prevention of respiratory syncytial virus (RSV)-mediated lower respiratory tract disease in a phase 2b study. In addition to neutralizing antibodies, Fc-effector functions are associated with protective immunity against RSV. Here, vaccine-induced Fc-effector functions were evaluated for the Ad26.RSV.preF/RSV preF protein vaccine in a subset of participants enrolled in a phase 1/2a study. RSV preF-specific antibody subclasses, isotypes, Fcγ receptor binding, and Fc-effector functions were evaluated on days 1 (pre-vaccination), 15, 29, and 183. Compared with Ad26.RSV.preF or RSV preF protein alone, the combination vaccine induced greater Fc-effector functions, including antibody-dependent neutrophil phagocytosis and antibody-dependent natural killer cell activation. Despite RSV pre-exposure, antibody-dependent neutrophil phagocytosis and antibody-dependent natural killer cell activation were not observed at baseline but were induced 