Mucosal vaccine based on attenuated influenza virus and the group B Streptococcus recombinant peptides protected mice from influenza and S. pneumoniae infections

Abstract

Although many influenza-related deaths are attributable to secondary bacterial infection with S . pneumoniae , vaccines that simultaneously protect against influenza and pneumococcal infection are currently not developed. The aim of our study was to evaluate the possibility to prevent post-influenza pneumococcal infection using an associated vaccine based on live influenza vaccine (LAIV) combined with recombinant polypeptides derived from superficial factors of Group B streptococcus (GBS) determining pathogenicity. We demonstrated in a model of post-influenza pneumococcal pneumonia that intranasal pneumococcal super-infection seriously complicated the course of A/Shanghai/2/2013(H7N9) CDC-RG virus infection in mice. Associated immunization using LAIV and GBS vaccine (GBSV) prevented post-influenza pneumococcal pneumonia better than mono-LAIV or GBSV immunization. At the same time, parenteral pneumococcal post-influenza infection of immune mice was more severe in the groups immunized using recombinant GBS peptides which can be explained by antibody-dependent enhancement of infection. In this case, the introduction of blockers of histamine receptors type 1 and 2 reduced the burden of secondary pneumococcal infection.

Mast cell degranulation and histamine release during A/H5N1 influenza infection in influenza-sensitized mice

“…In our previous studies, a model of virus-bacterial vaccination against influenza and pneumococcal complications of influenza showed an antibody-dependent increase in pneumococcal infection in mice with high titers of antibodies to the surface streptococcal proteins. This effect was also stopped by the introduction of antihistamines, which confirmed the role of histamine produced by mast cells in the development of severe systemic infection [ 34 ].…”

Associated virus-bacterial vaccine based on seasonal LAIV and S. pneumoniae chimeric peptide provide protection against post-influenza pneumococcal infection in mouse model

“…Development of mucosal vaccines based on LAIV and surface pathogenicity factors of S. pneumoniae is a novel approach of prevention bacterial complications of influenza infection. It was shown in mice that the joint intranasal implementation of vaccine influenza viruses of the pandemic or potentially pandemic subtype in combination with the recombinant peptides of streptococcus and pneumococcus more successfully prevent the development of severe post-influenza pneumonia in comparison with immunization with LAIV or bacterial polypeptides separately [ 11 , 12 ].…”