Protection of Pneumococcal Infection by Maternal Intranasal Immunization with Pneumococcal Surface Protein A

Abstract

Streptococcus pneumoniae is one of the important causative pathogens for both upper and lower respiratory tract infections during childhood. The current study was designed to evaluate the protection against fatal pneumococcal infections during the infant period by maternal immunization with pneumococcal surface protein A (PspA). Four-week-old females BALB/c mice were immunized with PspA and cholera toxin B (CTB) intranasally twice a week for 3 weeks. After mating, the 10-day-old offspring of these mice were intraperitoneally (i.p.) infected with S. pneumoniae to evaluate survival. Anti-PspA-specific IgG antibody was induced in the sera of mother and offspring. The survival times to death after systemic fatal pneumococcal infections were significantly extended among offspring delivered from PspA-immunized mothers than the controls. Current findings suggest that maternal intranasal immunization with PspA is an attractive procedure against pneumococcal infections in early childhood.