Intranasal delivery of nanoparticle-based vaccine increases protection against S. pneumoniae

Nanoparticle (NP) technologies are becoming commonplace in the development of vaccine delivery systems to protect against various diseases. The current study determined the efficacy of intranasal delivery of a 234 +/- 87.5 nm poly lactic-co-glycolic acid nanoparticle vaccine construct in establishing protection against experimental respiratory pneumococcal infection. Nanoparticles encapsulating heat-killed Streptococcus pneumoniae (NP-HKSP) were retained in the lungs 11 days following nasal administration compared to empty NP. Immunization with NP-HKSP produced significant resistance against S. pneumoniae infection compared to administration of HKSP alone. Increased protection correlated with a significant increase in antigen-specific Th1-associated IFN-gamma cytokine response by pulmonary lymphocytes. This study establishes the efficacy of NP-based technology as a non-invasive and targeted approach for nasal-pulmonary immunization against pulmonary infections.