Intranasal Immunization With an Attenuated pep27 Mutant Provides Protection From Influenza Virus and Secondary Pneumococcal Infections.

During influenza pandemics, secondary pneumococcal infections cause excessive mortality. However, the current 13-valent pneumococcal conjugate vaccine, PCV13, provides only limited protection against secondary infection. Therefore, a more effective pneumococcal vaccine is required to protect against secondary pneumococcal infections. Here, intranasal immunization with an attenuated pneumococcal pep27 mutant provides protection from influenza virus infection, and also from secondary pneumococcal challenge. These results indicate that mucosal immunity might be an effective way to reduce the morbidity and mortality due to secondary pneumococcal infections during influenza pandemics.