The comparative analysis of the biological characterization and the genetic background study of EV71 circulating strains is commonly recognized as basic work necessary for development of an effective EV71 vaccine. In this study, we sequenced five EV71 circulating strains, isolated from Fuyang, Hefei, Kunming and Shenzhen city of China and named them FY-23, FY-22, H44, K9 and S1 respectively. The sequence alignment demonstrated their genotypes be C4. The genetic distance of the VP1 gene from these isolates suggested that they were highly co-related with genetic identity similar to other previously reported EV71 strains in China. Additionally, these strains were identified to display some obvious proliferation dynamics and plaque morphology when propagated in Vero cells. However, a distinctive difference in pathogenic ability in neonatal mice was found. Some differences in cross neutralization test & immunogenic analysis were also found. All these results are related to the biological characterization of circulating EV71 strains in China and aid in the development of an EV71 vaccine in the future.

OBJECTIVE: To determine the immune-protective effect of Japan Schistosoma (Chinese mainland strain) 23 kD membrane protein-heat shock protein (SjC23-Hsp70) DNA vaccine plus adjuvantinduced interleukin-12 (IL-12) plasmid DNA on Schistosoma japonicum infection in water buffalos. METHODS: Forty-five health water buffalos (8-10 months old) in non-endemic area of schistosomiasis were randomly assigned into group A (SjC23-Hsp70+IL-12, 300 μg), group B (SjC23+IL-12, 300 μg) and group C (pVAX+IL-12, 300 μg), 15 in each group. Each buffalo was immuned by shoulder intramuscular injection for 3 times, at an interval of 28 days. Twenty-eight days after the last immunization, each buffalo was infected with 1000 Japan cercariae of Schistosoma. Fecal examinations were conducted 2 days and 1 day before the perfusion, and on the day of perfusion. The number of hatching miracidia and eggs per gram feces was recorded. Fifty-six days after the infection, the buffalos were sacrificed and perfused via the descending aorta. The recovered adult worms and eggs in the liver tissue were counted. RESULTS: We compared group A and B with group C: the estrogen reduction rate was 45.7% and 26.61%; bug reduction rate was 44.51% and 25.84%; the fecal egg reduction rate was 41.1% and 31.63%; the miracidium reduction rate was 48.11% and 38.07%; and the liver egg reduction rate was 43.39% and 31.95%. The above rates in group A were higher than those in group B (P<0.05). CONCLUSION SjC23-Hsp70 DNA vaccine combined with IL-12 may have a significant immunoprotective effect on buffalos.
Animals ; Antigens, Helminth ; immunology ; Buffaloes ; Cattle ; HSP70 Heat-Shock Proteins ; genetics ; immunology ; Helminth Proteins ; immunology ; Immunization ; methods ; Interleukin-12 ; genetics ; immunology ; Membrane Proteins ; immunology ; Schistosomiasis japonica ; immunology ; prevention & control ; veterinary ; Vaccines, DNA ; administration & dosage ; immunology ; Vaccines, Synthetic ; immunology

Objective To investigate the dynamic changes of three types of anti-poliovirus neutralizing antibodies and anti-hepatitis A virus (HAV) IgG antibody in children who were immunized with inactivated enterovirus 71 (EV71) vaccine (human diploid cell).Methods Serum samples were collected from the subjects immunized with inactivated EV71 vaccine.Neutralizing antibodies against EV71 and poliovirus were detected by micro-cytopathic effect neutralization test.Enzyme linked immunosorbent assay (ELISA) was used to detect IgG antibody against HAV.Results The geometric mean titers (GMTs) of anti-EV71 neutralizing antibody increased to 4.85 following the first-dose injection of inactivated EV71 vaccine.A significant increase of GMTs (up to 64.37) could be observed 28 days after the second-dose vaccination.Meanwhile, results of the dynamic monitor showed that there were slight fluctuations in the neutralizing antibodies against three types of poliovirus on day 28 (28 days after the first-dose vaccination) compared with those on day 0 (before vaccination) (P<0.05);types Ⅰ and Ⅲ anti-poliovirus neutralizing antibodies on day 56 (28 days after the second-dose vaccination) remained slightly different from those on day 0 (P<0.05), but type Ⅱ anti-poliovirus neutralizing antibody on day 56 had restored to normal level (P>0.05).The level of anti-HAV IgG antibody was stable and no significant difference was found during the observation period (P>0.05).Conclusion This study shows that inactivated EV71 vaccine has no impact on anti-HAV IgG antibody in Children during the two-dose vaccination and in anti-EV71 antibody-producing period, but has slight influence on the anti-poliovirus antibodies.In general, changes in antibody profile do not affect the clinical efficacy of immune response.