title: Effective protection against secondary pneumococcal pneumonia by oral vaccination with attenuated Salmonella delivering PspA antigen in mice.
abstract: Influenza infection followed by pneumococcal infection can cause severe pneumonia and this secondary pneumococcal pneumonia is the most common cause of influenza-associated death. Therefore, vaccination against Streptococcus pneumoniae is highly desirable for reducing the disease burden caused by seasonal epidemic and pandemic influenza. In this study, mice were vaccinated orally with a recombinant attenuated Salmonella vaccine (RASV) strain that delivers pneumococcal surface protein A (PspA) in order to examine protective efficacy against secondary pneumococcal pneumonia. A single dose of oral RASV resulted in attenuated pulmonary inflammation and effective protection against secondary pneumococcal pneumonia. Additionally, oral RASV induced long-term protection against secondary pneumococcal pneumonia. Treatment with an antiviral drug (i.e., oseltamivir) after treatment with RASV further prevented pulmonary inflammation after secondary pneumococcal infection. These results imply that oral RASV can protect mice from secondary pneumococcal infection after influenza infection and that vaccination against respiratory bacterial pathogens is a promising approach for dampening the impact of annual epidemic and pandemic influenza outbreaks.
authors.affiliation: Mucosal Immunology Section, Laboratory Science Division, International Vaccine Institute, Seoul 151-818l, Republic of Korea.
authors.forename: Sang-Uk
authors.initials: SU
authors.lastname: Seo
authors.forename: Jae-Jin
authors.initials: JJ
authors.lastname: Kim
authors.forename: Hyungjun
authors.initials: H
authors.lastname: Yang
authors.forename: Hyung-Joon
authors.initials: HJ
authors.lastname: Kwon
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Yang
authors.forename: Roy
authors.initials: R
authors.lastname: Curtiss Iii
authors.forename: Mi-Na
authors.initials: MN
authors.lastname: Kweon
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D051379:Mice; D008810:Mice, Inbred C57BL; D009976:Orthomyxoviridae Infections / Q000150:complications; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D011018:Pneumonia, Pneumococcal / Q000276:immunology / Q000517:prevention & control*; D022562:Salmonella Vaccines / Q000008:administration & dosage / Q000276:immunology; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D022242:Pneumococcal Vaccines; D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; C051592:pneumococcal surface protein A