Study on comprehensive monitoring of mouse and effect of hemorrhagic fever with renal syndrome vaccine in high prevalence areas of natural focus infectious disease of Zhejiang province in 1994--2010 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the comprehensive monitoring mechanism of mouse and the effect of hemorrhagic fever with renal syndrome (HFRS) vaccine in the high prevalence areas of natural focus infectious disease of Zhejiang province in 1994 - 2010.</p><p><b>METHODS</b>The night trapping method was used to monitor the population proportion, density and the rate of hantavirus (HV) carriers in mice in Xikou township Longyou county in August and September from 1994 to 2010. The healthy residents in Xikou township aged 16 to 60 years were recruited. The subjects were randomly selected as vaccination group and control group according to age, sex, occupational distribution (10 178 in intervention group and 16 159 in control group). Intervention group was given purified and inactivated vaccine from suckling mouse brain, while the control group received no intervention. The prevention effect was evaluated by protective rate of vaccine.</p><p><b>RESULTS</b>The mouse population was stable in the sixteen years and the apodemus agrarius was the main type (76.5% (564/737)). The average density of mouse was 4.73% (1170/24 727). The average rate of virus carrier of mouse was 3.87% (41/1033). In 1994 - 1995, the density of mouse was 22.82% (186/815) and the rate of virus carrier was 7.0% (10/143). In 2009 - 2010, the density of mouse decreased to 2.75% (119/4330) and the rate of virus carrier was 5.5% (13/237). The average antibody positive rate of mouse from 2005 to 2010 was 4.8% (35/728) and the rate was 4.4% (6/138), 0.0% (0/113), 11.8% (16/136), 1.0% (1/104), 3.7% (4/109) and 6.3% (8/128) in each year (P < 0.01). The protective rate of HFRS vaccine was 96.2% (1 case in intervention group and 41 cases in control group).</p><p><b>CONCLUSION</b>The density of mouse decreased significantly in Zhejiang province. The rate of virus carrier of mouse is stable. The vaccine is effective.</p>

Evaluation on the efficacy of recombinant hepatitis B vaccine booster immunization in 2789 children aged oner 10 years / 中华流行病学杂志

Objective To study the efficiency of booster immunization with different recombinant hepatitis B vaccines.Methods 2789 children aged over 10 years who had completed the basic immunization of hepatitis B vaccine under 1 year old were selected.All the sampled children were classified into four groups (A,B,C and D) and immunized with different hepatitis B vaccines produced by different campanies respectively.Before booster immunization,their blood plasma specimens were detected for hepatitis B virus (HBV) surface antigen (HBsAg),antibodies to HBV surface antigen (anti-HBs) and antibodies to HBV core antigen (anti-HBc) by chemiluminescence.In each group,the anti-HBs positive children were immunized with one dosage and anti-HBs negative children were immunized three dosages of the same vaccine.Their blood specimens were collected again after 1 month,and detected for anti-HBs.Results The anti-HBs positive rates of A,B,C and D group were 36.43%,37.59%,42.91% and 46.46% respectively before immunization while 89.20%,91.52%,90.96% and 85.45% respectively after immunization with one dosage,99.12%,99.47%,98.87% and 98.85% respectively after immunization with three dosages.The differences of anti-HBs positive rates in the four respective groups showed statistical significances between any two rates of pre-immunization,post-immunization with one dosage and post- immunization with three dosages (all P＜0.05).The anti-HBs positive conversion rates of four groups were 83.01%,86.41%,84.16% and 72.82% respectively after immunization with one dosage.The anti-HBs positive conversion rate of four groups were 98.62%,99.16%,98.03% and 97.84% respectively after immunization with three dosages and the difference of positive conversion rates in each group showed statistical significances between booster immunization with one dosage and booster immunization with three dosages.The average GMTs in anti-HBs positive children in the four groups were 2853.21,6254.23,3581.40 and 3021.32 mIU/ml respectively after immunization with one dosage.The average GMTs of anti-HBs negative children in the four groups were 273.08,648.52,387.87 and 245.36 mIU/ml respectively after immunization with one dosage,and were 632.30,2341.14,563.97 and 394.08 mIU/ml respectively after immunization with three dosages.Conclusion Our data showed that it would be suitable to anyone to use the four vaccines for anti-HBs positive children aged over 10 years with one dosage and for anti-HBs negative children aged over 10 years with three dosage booster immunization.

Study on a 10-year protective effects of vaccination against hemorrhagic fever with renal syndrome / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the epidemiological and serological efficacy after 10 years of vaccination against hemorrhagic fever with renal syndrome (HFRS) vaccines in Zhejiang province.</p><p><b>METHODS</b>One county was randomly chosen as the research unit with all the healthy people between 16 and 60 years old were equally divided into study and control groups. The study group was vaccinated. Immunofluorescent antibody assay was used to test specific IgG antibody and Mcro-CPE method was used to test the titer of neutralizing antibody.</p><p><b>RESULTS</b>Two weeks after the full-course immunization, the seroconversion rate became 100% (67/67, with 95% CI as 96.3%-100%) by immunofluorescent antibody test (IgG) and 44.4% (8/18 with 95% CI as 22.0%-69.0%) by neutralization test with GMT titers as 72.1 and 4.6 respectively. Booster immunization was provided one year later. Time span as two weeks prior to, one year, one and half years, two years, three years and five years after booster immunization, the rates of seroconversion on immunofluorescent antibody using IFAT method, were 28.6%, 83.3%, 75.0%, 53.1%, 22.6%, 10.0% and 55.0% respectively, and rates of seroconversion of neutralizing antibody by Mcro-CPE method were 14.8%, 55.6%, 35.0%, 31.3%, 26.0%, 10.0% and 50.0% respectively. Nine years after the reinforcement, the rates of seroconversion of immunofluorescent antibody by IFAT method was only 7.1%. The vaccinated group had no patient seen but the control group appeared 34 patients including 3 deaths. According to the ten-year observation, the vaccine seemed effective with the protection rate in population reached 100%.</p><p><b>CONCLUSION</b>HFRS vaccine was effective on epidemiological, social and economical efficacy.</p>

Serological surveillance on vaccine against hemorrhagic fever with renal syndrome / 中华流行病学杂志

<p><b>OBJECTIVE</b>To observe the serological and epidemiological efficacy of hemorrhagic fever renal syndrome (HFRS) vaccine in Zhejiang province.</p><p><b>METHODS</b>Immunofluorescent antibody assay and Mcro-CPE method were used to test specific IgG antibody and the titer of neutralizing antibody.</p><p><b>RESULTS</b>Two weeks after the injection of the third dose, the sero-conversion rates by both immunofluorescent antibody test (IgG) and neutralization test were 100.0% (67/67) (95% CI: 96.3 - 100.0) and 44.4% (8/18)(95% CI: 22.0 - 69.0) with geometric mean titers (GMTs) 72.1 and 4.6 respectively. The rates of seroconversion of immunofluorescent antibody by immunofluorescence antibody assay (IFA) were 28.6%, 83.3%, 75.0%, 53.1%, 22.6%, 10.0% and 55.0% before reinforcement, two weeks, one year, one year and a half years, two years, three years and five years after reinforcement. The rates of neutralizing antibody seroconversion by the Mcro-CPE method were found as 14.8%, 55.6%, 35.0%, 31.3%, 26.0%, 10.0% and 50.0% respectively. We found some antibody dependent immunization enhancement phenomenon among the inoculated population, but further observation was needed.</p><p><b>CONCLUSION</b>HFRS vaccine was immunologically effective and the duration of serous antibody last long.</p>