Search

Abstract: A formalin-inactivated West Nile Virus (WNV) vaccine (WN-VAX) derived from the WNV-NY99 strain was tested for its safety, efficacy, dilution limit for complete protection, and cross-neutralization. Safety tests performed with experimental animals, bacteria, or cultured cell lines showed no evidence of short- or long-term adverse effects. WN-VAX also protected 100% of 4-week-old mice against a lethal challenge from the WNV-NY99 strain after two doses of intraperitoneal inoculation—even when the vaccine was diluted to 3.2ng/dose. Moreover, very limited cross-neutralization activity against Japanese encephalitis virus, Dengue virus, Murray Valley encephalitis virus, Yellow fever virus or St. Louis encephalitis virus was observed. Therefore, the WN-VAX satisfies the requirements for human trials planned to be done in Japan. [ABSTRACT FROM AUTHOR]

Abstract: Japanese encephalitis is an infectious disease caused by the Japanese encephalitis virus, which is widespread throughout Asia. The worldwide incidence is 50,000 cases per year. There is no specific treatment available, but inactivated mouse brain-derived vaccine was used from the 1950s to prevent infection. However, quality control of mouse brain-derived vaccines is difficult, and therefore a new freeze-dried, cell culture-derived Japanese encephalitis vaccine (inactivated) (JEBIK V; development code: BK-VJE) was developed. In this paper, we report an analysis of neutralizing antibody titers in vaccinated subjects enrolled in clinical study of BK-VJE at various doses, and study of BK-VJE with the mouse brain-derived vaccine as a control. The results show that BK-VJE has superior immunogenicity compared to mouse brain-derived vaccine. [Copyright &y& Elsevier]

The recombinant neuraminidases (rNAs) from A/New Caledonia/20/99 (NC) (H1N1), A/PR/8/34 (PR8) (H1N1), A/Panama/2007/99 (Panama) (H3N2) and B/Shangdong/7/97 (B/S) viruses were produced by the CHO-K1 cells, prepared from clones which were selected based on the high expression of NA on the cell surface. Each rNA in the cell lysate was purified by an immuno-affinity column. The purified rNAs were obtained at the levels of approximately 0.6–1.8 mg/l medium. Properties of the recombinant N1-NA from NC virus was compared with other rNAs from PR8, Panama and B/S viruses, because N1-NA remained to be characterized. The results demonstrated that the immunogenicity of N1-rNA molecules, such as NC-NA and PR8-NA, was conserved partially even under the absence of the NA enzymatic activity, although the N1-rNA molecules were more labile than Panama-N2-rNA and B/S-rNA. They also suggested that N1-rNAs could be used as a useful protective antigen, capable of producing cross-protection among N1 influenza viruses when administered intranasally. [Copyright &y& Elsevier]

Background: West Nile virus (WNV) belonging to the genus Flavivirus of the family Flaviviridae causes nervous system disorder in humans, horses and birds. Licensed WNV vaccines are available for use in horses but not for humans. We previously developed an inactivated West Nile virus vaccine (WN-VAX) using a seed virus from West Nile virus (WNV NY99) that was originally isolated in New York City in 1999. In this study, we report the immunogenicity of WN-VAX in both mice and non-human primates., Findings: The WN-VAX immunized mice showed protection against lethal infection with WNV NY99. The challenge test performed on mice passively immunized with serum from other mice that were previously immunized with WN-VAX confirmed that the neutralizing antibody titers of more than 1log10 protected the passively immunized mice from WNV lethal infection. Furthermore, monkeys (Macaca fascicularis) immunized three times with 2.5 μg, 5 μg or 10 μg/dose of WN-VAX exhibited neutralizing antibodies in their sera with titers of more than 2log10 after the second immunization., Conclusions: The WN-VAX was protective in mice both by active and passive immunizations and was immunogenic in monkeys. These results suggest that the vaccine developed in this study may be a potential WNV vaccine candidate for human use.