title: Single dose of inactivated Japanese encephalitis vaccine with poly(gamma-glutamic acid) nanoparticles provides effective protection from Japanese encephalitis virus.
abstract: Japanese encephalitis (JE) is a serious disease caused by the JE virus (JEV), and vaccination is the only way to prevent the diseases. In Japan, the only JE vaccine currently available is an inactivated vaccine that requires multiple doses for effective protection; therefore, an effective single-dose vaccine is needed. However, no report of an effective protocol for a single dose of JE vaccine in animals has been published. Here, we evaluated the efficacy of a single-dose vaccination in mice to which the JE vaccine was given with or without adjuvant. Biodegradable poly(gamma-glutamic acid) nanoparticles (gamma-PGA-NPs) were used as a test adjuvant. Remarkably, a single dose of JE vaccine with gamma-PGA-NPs enhanced the neutralizing antibody titer, and all of the immunized mice survived a normally lethal JEV infection, while only 50% of the mice that received a single dose of JE vaccine without gamma-PGA-NPs survived. The use of aluminum as the adjuvant showed similar levels of enhanced efficacy. These results show that gamma-PGA-NPs are a novel and safe adjuvant for JE vaccine, and that a single dose of JE vaccine with gamma-PGA-NPs provides effective protection from lethal JEV in mice. A similar protocol, in which a single dose of JE vaccine is mixed with gamma-PGA-NPs, may be useful for the immunization of humans.
authors.affiliation: Laboratory of Virology and Vaccinology, Division of Biomedical Research, National Institute of Biomedical Innovation, 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan.
authors.forename: Shigefumi
authors.initials: S
authors.lastname: Okamoto
authors.forename: Hironori
authors.initials: H
authors.lastname: Yoshii
authors.forename: Toyokazu
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Takami
authors.initials: T
authors.lastname: Akagi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Akashi
authors.forename: Michiaki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamanishi
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D004353:Drug Evaluation, Preclinical; D004672:Encephalitis, Japanese / Q000517:prevention & control*; D005260:Female; D007114:Immunization; D007115:Immunization Schedule; D007274:Injections, Intraperitoneal; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage*; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000008:administration & dosage*; D011099:Polyglutamic Acid / Q000008:administration & dosage*; D015164:Vaccines, Inactivated / Q000008:administration & dosage
chemical_list: D000276:Adjuvants, Immunologic; D022321:Japanese Encephalitis Vaccines; D015164:Vaccines, Inactivated; D011099:Polyglutamic Acid