Influenza B Virus DNA Vaccine And Adjuvant Effect Of CpG Motif

In this study, various doses of HA DNA and NA DNA were inoculated alone or as a mixture into mice once by electroporation. Four weeks after immunization, the mice were challenged with a lethal dose of influenza B virus. The induced serum IgG antibody levels and the survival rates of mice were measured to evaluate the immunity efficacy of the DNA vaccines. The results showed that a single dose of 100μg HA DNA or 10μg NA DNA provided 100% protection in mice against the lethal challenge. Moreover, when the two plasmid DNAs were coinoculated into mice, a single dose of 5μg of tne two plasmids each provided 100% protection. These indicate that a single immunization of HA DNA, NA DNA or a mixture of HA DNA and NA DNA would be an efficient method in preventing influenza B virus infection.To investigate the immune response induced by one or two times of inoculation with influenza B virus HA DNA vaccine and the adjuvant effect of CpG motif, BALB/c mice were immunized i.m. by electroporation once or twice (at a 3- week interval ) with plasmid HA DNA at different doses. Four weeks after the first inoculation (or one week after the second inoculation), the mice were challenged with a lethal dose of influenza virus (B/Ibaraki/2/85). The experiments showed that: 1) mice immunized with a single dose of 100μg HA DNA all...