Protective Efficacy against Respiratory Syncytial Virus following Murine Neonatal Immunization with BBG2Na Vaccine: Influence of Adjuvants and Maternal Antibodies

• DOI: 10.1086/314778
• Publication Date: 2002-07-26T14:58:45Z
• Authors: Claire‐Anne Siegrist; Hélène Plotnicky‐...; Marco Córdova; Monika Berney; Jean‐Yves Bonnefoy; Thien Ngoc Nguyen; Paul‐Henri Lambert; Ultan F. Power
• Keywords: 0301 basic medicine; Respiratory Syncytial Virus Infections; 618; Mice; Viral Proteins; 03 medical and health sciences; Adjuvants, Immunologic; Viral Envelope Proteins; name=Public Health; 616; Animals; name=Immunology; /dk/atira/pure/subjectarea/asjc/2400/2403; Mice, Inbred BALB C; Vaccines, Synthetic; HN Protein; Environmental and Occupational Health; Vaccination; Viral Vaccines; /dk/atira/pure/subjectarea/asjc/2700/2739; name=SDG 3 - Good Health and Well-being; 3. Good health; Animals, Newborn; /dk/atira/pure/sustainabledevelopmentgoals/good_health_and_well_being; Immunity, Maternally-Acquired

Alum-adsorbed BBG2Na, a recombinant vaccine derived in part from the respiratory syncytial virus (RSV) subgroup A G protein, induced moderate antibody titers after 1 immunization in 1-week-old mice but conferred complete lung protection upon RSV challenge. The anti-BBG2Na IgG1-IgG2a neonatal isotype profile was suggestive of dominant Th2 responses compared with those in adults. Formulation of BBG2Na with a Th1-driving adjuvant efficiently shifted neonatal responses toward a more balanced and adultlike IgG1-IgG2a profile without compromising its protective efficacy. BBG2Na-induced protective immunity was maintained even after early life immunization in the presence of high titers of maternal antibodies. Under these conditions, the protective efficacy (86%-100%) reflected the high capacity of the nonglycosylated G2Na immunogen to escape inhibition by RSV-A-induced maternal antibodies. Thus, immunization with BBG2Na protected against viral challenge despite neonatal immunologic immaturity and the presence of maternal antibodies, two major obstacles to neonatal RSV vaccine development.