The effect of hepatitis B vaccination after five years on an entire population in an insular region of Southeast China.

Prevalence of hepatitis B (HB) remains high among adults in insular regions of southeast China. To address this issue, large-scale HB vaccination was implemented in Putuo County of Zhoushan City in 2013. To examine the effects of this large-scale HB vaccination, a cross-sectional serological survey was conducted on two isolated islands, Putuo (intervention group) and Dinghai (control group) Counties of Zhoushan City in southeastern China five years later. The data showed lower prevalence of HBsAg and negative results for all HBV markers in the intervention group compared to the control group (4.2% and 6.0%, 20.8% and 33.0%), while the positive rate for anti-HBs and only anti-HBs were higher (68.4% and 53.4%, 47.9% and 34.3%). Therefore, large-scale adult HB vaccination could lower the HB epidemic level. However, the proportion of susceptible people who were negative for all HBV markers remained high. Hence, several additional measures to limit the spread of HBV should be taken by the government.

Aerodynamic Performance of an Adaptive GFRP Wind Barrier Structure for Railway Bridges.

Wind barrier structures on railway bridges are installed to mitigate the wind effects on travelling trains; however, they cause additional wind loads and associated aerodynamic effects on the bridge. An innovative concept was developed for a wind barrier structure in this study that used a glass-fibre-reinforced polymer (GFRP) that may deform properly when subjected to a crosswind. Such deformation then allows for wind to pass, therefore reducing the wind loads transferred to the bridge. Wind tunnel experiments were conducted on a 1/40-scale train and bridge models with the proposed GFRP barrier subjected to airflow at different speeds up to 20 m/s. The side-force and overturning-moment coefficients of both the train and the bridge were evaluated to characterise the aerodynamic effects. The results show that favourable side-force and overturning-moment coefficients of the train were provided by wind barriers taller than 10 cm. The aerodynamic coefficients of the train were not significantly affected by the airflow speeds; meanwhile, the overturning-moment coefficient of the bridge decreased with the increase in airflow speed due to smaller wind resistance of the barrier after deformation. A numerical analysis was conducted on both the reduced- and full-scale models of the train-barrier-bridge system and the results supported the findings obtained from the wind tunnel experiments.

Strategies for hepatitis B booster vaccination among children: an 8-year prospective cohort study.

Debate continues regarding the need for a booster vaccination in children who received a universal infant hepatitis B virus (HBV) vaccination. The aim was to explore the need and the strategies for the booster HBV vaccination. 8-year prospective cohort study was conducted among children aged 5-15 years in 2009-2010 in Zhejiang Province. The participants were divided into groups A (<0.1 mIU/mL), B (0.1 to < 1 mIU/mL) and C (1 to <10 mIU/mL) according to the pre-booster anti-HBs antibody levels. 5 µg (group I), 10 µg (group II), 20 µg hepatitis B vaccines (group III) or 5 µg hepatitis A and B (HAB) vaccines (group IV) with 0-1-6-month schedule were randomly administered to children negative for all markers. Blood samples were collected at baseline HBV marker testing, 1 month after the first dose, 1 month, 1 year, 5 years and 8 years after the third dose. Among 4170 children, 2326 (55.8%) were negative for all HBV markers. Group II showed the highest seropositive rates of 92.8%, 99.7%, 97.6%, 90.3% and 83.4% with GMTs of 4194.5 mIU/ml, 4163.9 mIU/ml, 466.9 mIU/ml, 190.6 mIU/ml, 122.6 mIU/ml from 1 month after dose 1 to 8 years after dose 3, respectively (P < .01). Participants in group C showed seropositive rates of 98.9%, 99.9%, 99.5%, 95.5%, 92.8% after the revaccination with GMTs of 6519.6 mIU/ml, 5267.4 mIU/ml, 547.1 mIU/ml, 249.5 mIU/ml, 155.3 mIU/ml, respectively, higher than group A and B (P < .001), except 1 month after the third dose. The 10 µg of HBV vaccine with a 0-1-6-month booster regimen may elicit robust responses and persist for 8 years or longer. Additionally, 1-dose revaccination maybe suitable for children with 1 to < 10 mIU/ml anti-HBs titers.

Long-term persistence of anti-HBs after hepatitis B vaccination among adults: 8-year results.

The long-term persistence of hepatitis B surface antibody (anti-HBs) after hepatitis B vaccination among adults was not known clearly. This study aimed to assess the immunogenicity and persistence of antibodies 8 years after hepatitis B immunization with different vaccination schedules among adults who tested negative for hepatitis B surface antigen (HBsAg), anti-HBs, and hepatitis B core antibody (anti-HBc). A total of 771 participants who received the full vaccination course (three doses) and also had a blood sample taken 1 month after the first vaccination were recruited. Of these, 529 were excluded due to the missing data of anti-HBs 8 years after the first vaccination. Vaccinations were carried out at 0-1-3, 0-1-6 and 0-1-12 month vaccination schedules, and 104, 45, and 93 participants were included, respectively. The positive seroprotection rate was 85.9% 1 month after the third vaccination, and 58.3% 8 years later (χ2 = 54.52, P < .001), while the geometric mean titer (GMT) of anti-HBs was 158.49 mIU/mL [95% confidence interval (CI): 131.83-190.55)] and 15.14 mIU/mL (95% CI: 10.96-20.42) after 1 month and 8 years, respectively. Compared with the standard 0-1-6 month vaccination schedule, the positive seroprotection rate and the GMT of the 0-1-3 month vaccination schedule had no difference. The long-term immune effect of the 0-1-3 month vaccination schedule was better than that of the 0-1-12 month vaccination schedule. No correlation was found between the GMT of anti-HBs 1 month and 8 years later.

Responses to hepatitis B vaccine in isolated anti-HBc positive adults.

Immune responses of isolated anti-HBc subjects are not well characterized in populations in China. This study aimed to evaluate immune responses to hepatitis B vaccination in isolated anti-HBc positive subjects. A cohort of 608 subjects were selected and separated into isolated anti-HBc (negative for HBsAg and anti-HBs, positive for anti-HBc) and control (negative for HBsAg, anti-HBs, and anti-HBc) groups, who were matched by age and sex. All subjects received 3 doses of hepatitis B vaccine (20µg) at months 0, 1, and 3, followed by testing for serological responses 1 month after the third vaccination. The positive seroprotection rate and geometric mean titer (GMT) for hepatitis B surface antibody (anti-HBs) of isolated anti-HBc subjects were significantly lower than those in the control group(86.2% vs.92.1%, P = 0.02; 47.26 vs.97.81 mIU/mL, P < 0.001). When stratified by age, positive seroprotection rate in the isolated anti-HBc group were 92%, 88.5% and 79.4% in the 20-34, 35-49, and 50-60 y old subgroups, respectively (χ2 = 5.919, P = 0.04). Additionally, the GMT level for anti-HBs in the isolated anti-HBc group for different age subgroups were 104.43, 47.87 and 31.79 mIU/mL respectively (χ2 = 19.44, P < 0.001). The GMT level for anti-HBc before vaccination were negatively correlated with GMT for anti-HBs after 3 doses of hepatitis B vaccine (r = -0.165, P < 0.001). In conclusion, isolated anti-HBc positive subjects can achieve good immune responses after hepatitis B vaccination, and the positive seroprotection rate and GMT level for anti-HBs were lower than the control group. Better responses could be observed in young adults, and significant negative correlations were found between GMT of anti-HBc before vaccination and GMT of anti-HBs after vaccination.

Optimal vaccination program for healthy adults in China.

There is still no suitable routine hepatitis B immunization strategy for adults in China. To establish an optimal vaccination schedule for healthy adults, we investigated various schedules in healthy adults. In this randomized 5143 healthy adults received 10 µg hepatitis B vaccine at 0, 1 and 3 months(group A), 0, 1 and 6 months(group B), or 0, 1 and 12 months(group C). Blood samples were collected after 1 month and 12 months after the third dose. The geometric mean titer (GMT), seroconversion rate (levels of anti-HBs ≥ 10 mIU/mL) and high response rate (levels of anti-HBs ≥ 100 mIU/mL) were assayed. In our study, 2438 healthy adults finished the full vaccination program and follow-up. The seroconversion/sero-protective rate of groups A-C at one and 12 month after administration of the third vaccine dose was 100%, 99.9% and 97.9% verse 64.9%, 75.7% and 79.0%, respectively. GMT for anti-HBs tested in group A to C within 1 or 12 month after the third vaccination was 213.16, 432.58 and 451.47 mIU/ml verse 22.07, 46.70 and 56.18 mIU/ml, respectively. There were significant differences of seroconversion/sero-protective rate and GMT among the 3 groups (p < 0.01). Given the high anti-HBs seroconversion rate and GMT in all 3 groups, a flexible schedule for Hepatitis B vaccine should be recommended to adults, but 0-1-12 schedule is a better choice.

The one year effects of three doses of hepatitis B vaccine as a booster in anti-HBs-negative children 11-15 years after primary immunization; China, 2009-2011.

The aim of this study was to evaluate hepatitis B surface antibody (anti-HBs) levels one year after hepatitis B booster vaccination in anti-HBs-negative (<10 mIU/mL) children 11-15 y after primary vaccination. Anti-HBs titers were examined in 235 children who were negative for hepatitis B surface antigen (HBsAg), anti-HBs, and hepatitis B core antibody (anti-HBc). The children were then divided into 3 groups based on their anti-HBs levels pre-booster: Group I, <0 .1 mIU/mL; Group II, 0.1 to <1 .0 mIU/mL; and Group III, 1.0 to <10 .0 mIU/mL. They were vaccinated with 3 doses of hepatitis B vaccine (0-1-6 month, 20 ug), and anti-HBs levels were measured. One month after the first dose, the anti-HBs positive rates (≥ 10 mIU/mL) in Groups I-III were 56.14%, 83.61% and 100%. One month after the third dose, the anti-HBs-positive rates in Groups I-III were 96.49%, 98.36% and 100%. One year after the third dose, the anti-HBs-positive rates in Groups I-III were 73.68%, 75.41% and 98.29%, respectively. Protective levels declined more rapidly for those with lower titers. Children with pre-booster anti-HBs titers of 1-9.9 mIU/mL might not need any booster dose, and the children with pre-booster titers of 0.1-0.9 and <0 .1 mIU/mL might need more than one dose booster vaccination.

The response of hepatitis B vaccination on seronegative adults with different vaccination schedules.

The purpose of this study was to compare the response of hepatitis B vaccination with different vaccination schedules among seronegative adults, and to provide suitable vaccination schedules for floating and fixed population. The study included adults aged 20 to 39 y without prior history of vaccination with hepatitis B vaccine. The serum samples were collected and tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels. Out of all, 686 adults who were negative for anti-HBs, anti-HBc and HBsAg were vaccinated with 10 ug hepatitis B vaccine at 0, 1 and 3, 6 or 12 month schedules, and their antibody titers were monitored. The rates of completion of the vaccination in floating and fixed population were 90.4% and 94.1% respectively (p = 0.061). The anti-HBs positive rates in adults vaccinated at 0, 1 and 3 ,6 or 12 month were 83.9%, 88.2% and 94.2% respectively (P = 0.0003). The corresponding geometric mean titers (GMTs) were 61.19 (95%CI:47.10-81.23) mIU/mL, 214.04(95%CI:157.14-291.61) mIU/mL and 345.78(95%CI:251.25-475.77) mIU/mL, respectively ( P < 0.0001). Vaccination of hepatitis B with both 0-1-6 and 0-1-12 month schedules in adults result in better level of immune responses. Also, a longer vaccination schedule (0-1-12 month) may be more suitable for floating population and 0-1-6 month schedule is recommended for the fixed population.

[Determination of 18 polycyclic aromatic hydrocarbons in plastic products by ultra performance convergence chromatography].

A method for rapid determination of naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo (a) anthracene, chrysene, benzo(b) fluoranthene, benzo(k) fluoranthene, benzo(j) fluoranthene, benzo (e) pyrene, benzo (a) pyrene, indeno (1, 2, 3-cd) pyrene, dibenzo (a, h) anthracene, benzo (g, h, i) perylene in plastic products by ultra performance convergence chromatography (UPC2) coupled photodiode array detector (PAD) was developed. The 18 polycyclic aromatic hydrocarbons (PAHs) were successfully separated in less than 8.5 min on a Daicel IB-3 chiral column with a mobile phase of CO2, the mobile-phase additive of methanol/acetonitrile (25 :75, v/v) at column temperature of 40 degrees C, and a back pressure of 15.17 MPa. There was a linear correlation between peak area and PAH concentration in the range of 0.05-50 mg/L (r ≥ 0.999 5) for each PAH. The limits of quantification (LOQs)(S/N > 10) were 0.05 mg/L. After ultrasonic-assisted extraction in toluene, the sample was analyzed by UPC2-PDA. The recoveries of PAHs spiked in plastic samples were from 78.3% to 117.6%, and the repeatabilities of peak areas for the 18 PAHs were less than 5% (RSD, n = 5). The present UPC2-PDA method has the advantages of rapid speed, high resolution, and low organic reagent consumption.

Immunological effects of a 10-µg dose of domestic hepatitis B vaccine in adults.

OBJECTIVE: To evaluate the immunological effects of three types of domestic 10-µg/dose hepatitis B vaccines in adults compared with a foreign vaccine, and to provide scientific evidence in support of adult hepatitis B vaccination. METHODS: Adults from five counties (Deqing, Changxing, Nanxun, Wuxing, Anji) in Huzhou City, Shaoxing County and Tongxiang County, Zhejiang Province, China were selected. Blood samples were taken to assess serum HBsAg, anti-HBs, and anti-HBc using a chemiluminescence immunoassay. Adults, aged 16 to 49 years and who were anti-HBs negative at baseline, received hepatitis B immunizations at 0, 1, and 6 months. Anti-HBs levels were assessed one month after the third and final vaccination. RESULTS: A total of 1872 adults were immunized and the average positive rate was 89.5%. Four types of hepatitis B vaccine were used, including three from Chinese companies (Shenzhen Kangtai, Dalian High-Tech, and North China Pharmaceutical) and one from a UK company (GlaxoSmithKline). Their seroconversion rates were 81.67%, 95.05%, 89.64%, and 86.81%, respectively. There was a significant difference between the anti-HBs positive conversion rates of the four types (P<0.005) but the seroconversion rates among the different vaccines were not significantly different (χ(2)=2.123, P=0.145). The average anti-HBs geometric mean titers (GMTs) of non-immune adults immunized with each of the four vaccines were 177.28, 473.23, 246.13, and 332.20 mIU/ml, respectively. There were no statistically significant differences in the GMTs between the three types of domestic vaccine and the foreign vaccine (t=-1.575, P=0.116). CONCLUSIONS: Domestic recombinant hepatitis B vaccines can achieve immunization effects comparable to those of a foreign vaccine.