To evaluate the long-term efficacy and anamnestic response of Chinese hamster ovary (CHO) cell-derived hepatitis B vaccine (CHO-HepB) after 18-20 years, a cross-sectional survey was conducted in seven communities in Zhengding County at the end of 2017. The birth cohort 1997-1999 vaccinated primarily with three doses of CHO-HepB were enrolled in the survey. The HBV serological markers were quantified using the Chemiluminescence method. The infection status of HBsAg-positive participants was determined by comparing their results with the previous data. For those with an anti-HBs antibody negative, the anamnestic response was evaluated by measuring anti-HBs antibody concentrations following a dose of HepB administration. A total of 1352 participants were enrolled, with the prevalence of HBsAg, anti-HBs, and anti-HBc being 0.4 %, 74.5 %, and 1.3 %, respectively. There was no significant difference in the HBV markers (HBsAg, anti-HBs and anti-HBc) between birth-year groups (P > 0.05). The geometric mean concentration (GMC) of anti-HBs antibodies among 1007 positive participants was 191 mIU/ml. No new infections or carriers were identified in the survey. Combined with the three previous surveys of the same birth cohort, the positive rates of HBsAg, anti-HBs, and anti-HBc remained largely unchanged over two decades following CHO-HepB vaccination. Of 248 participants who received a booster vaccination, 231 (93.1 %) showed an anti-HBs antibody positive with a GMC of 369 mIU/mL. Moreover, the positive rate and GMC of anti-HBs were higher in the CHO-HepB booster group compared to the Saccharomyces cerevisiae-HepB booster group. The long-term efficacy of the CHO-HepB remains stable for 18-20 years after primary vaccination, and a higher seroconversion rate of anti-HBs is observed following a booster vaccination of CHO-HepB. Given the absence of new infections or carriers over the past two decades, it appears unnecessary to administer a booster vaccination of HepB.

目的 评价中国仓鼠卵巢细胞乙型肝炎(乙肝)疫苗(Chinese hamster ovary cell derived hepatitis B vaccine,HepB-CHO)接种后18-20年免疫持久性和回忆反应.方法 2017年10-11月在河北省正定县整群抽取1997-1999年出生且接种3剂次HepB-CHO的受试者开展问卷调查,采用化学发光法检测血清乙肝表面抗原(Hepatitis B surface antigen,HBsAg)、表面抗体(Hepatitis B surface antibody,HBsAb)和核心抗体(Hepatitis B core antibody,HBcAb),分析乙肝病毒标志物阳性率和HBsAb几何平均浓度(Geometric mean concentration,GMC);随机选择HBsAb和其他标志物均阴性的受试者,随机分为两组分别加强接种1剂次HepB-CHO和酵母细胞乙肝疫苗(Yeast cell derived HepB,HepB-Y),检测接种后30d血清HBsAb,比较抗体阳转率和GMC.结果 在1 352例受试者中,3剂次 HepB-CHO 接种后 18-20 年 HBsAg、HBsAb 和 HBcAb 阳性率分别为 0.4％(6 例)、74.5％(1 007 例)和 1.3％(18例),HBsAb阳性者HBsAb GMC为191mIU/mL.本次调查中HBsAg阳性者在2005年、2009年和2013年调查中均为阳性;4次调查显示同一队列的受试者HepB-CHO初次免疫后6-20年HBsAg、HBcAb和HBsAb阳性率未呈显著上升或下降趋势(趋势检验:x2=3.58,P＞0.05;x2=3.42,P＞0.05;x2=4.54,P＞0.05).248例HBsAb阴性受试者加强1剂次HepB-CHO或HepB-Y后HBsAb总阳转率为93.1％(231例),阳转者GMC为369mIU/mL;其中HepB-CHO、HepB-Y加强免疫受试者HBsAb阳转率分别为97.7％、88.3％(x2=8.43,P＜0.05),阳转者GMC分别为578mIU/mL、226mIU/mL(t=7.16,P＜0.05).结论 HepB-CHO初次免疫后18-20年具有良好的免疫持久性和回忆反应,提示普通人群无必要加强免疫.

Objective:To understand the situation of hepatitis B booster vaccination in population and its influencing factors, so as to provide reference for hepatitis B booster immunization.Methods:The study was conducted in Zhengding county which was the monitoring site for observing the immune effect of hepatitis B vaccine and Dingxing county. Participants who were born from 1986 to 2011 and had completed hepatitis B primary vaccination were enrolled. A questionnaire survey was carried out among the participants to analyze the situation of hepatitis B booster immunization. Logistic regression analysis was used to identify the influencing factors.Results:A total of 3 447 participants were included, and the rate of hepatitis B booster vaccination was 32.93% (1 135 participants). Logistic regression analysis showed that the people at the age of 18-27 and 28-34, as well as high school (technical secondary school) education level had high incidence of booster vaccination[ OR(95% CI)=1.485(1.173-1.879), 1.855 (1.362-2.525) and 1.500 (1.234-1.825)]. People who had a history of marriage, lived in city, took examination for hepatitis B actively had high incidence of booster immunization[ OR(95% CI)=1.636(1.277-2.097), 1.390(1.077-1.794) and 1.201 (1.000-1.443)]. People living with family members without hepatitis B had low incidence of booster immunization[ OR(95% CI)=0.255(0.099-0.657)]. People who didn’t know whether they lived with HBV carriers had low incidence of booster immunization[ OR(95% CI)=0.186(0.062-0.552)]. The incidence of booster immunization in people with the score of hepatitis B knowledge ≥16 was lower than that of ≤11 [ OR (95% CI)=1.789 (1.371-2.333)], and in people with the score of risk attitude 9-11 was higher than that of 5-8[ OR(95% CI)=1.472(1.149-1.886)]. Population in monitoring site had a lower incidence rate than those in non-monitoring site[ OR(95% CI)=0.304(0.248-0.372)]. Conclusions:The occurrence of hepatitis B booster vaccination is related to multiple factors. Strengthening the propaganda of hepatitis B and hepatitis B vaccine related knowledge can promote the occurrence of hepatitis B booster vaccination.

Objective:To investigate the sero-epidemiological features of HBV infection among people aged 1-29 years in Hebei province in 2014, so as to provide references for estimating the efficiency of measures on prevention and control of the disease.Methods:In 2014, a stratified two-stage cluster sampling method was used to select the subjects from local residents aged 1-29 years in 8 sites in Hebei province. A questionnaire survey was conducted to obtain basic information, including birth date, age, ethnicity, gender and so on. Blood samples were collected to detect HBV markers and statistical analysis was performed to compare the positive rates of HBsAg, anti-HBs and anti-HBc among different groups.Results:A total of 1 015 subjects aged 1-29 were involved in this survey in 2014. The positive rates of HBsAg, anti-HBs and anti-HBc were 1.08%, 53.50% and 6.60%, respectively. The positive rates of HBsAg, anti-HBs and anti-HBc had statistically significant differences among different age groups (1-4, 5-14 and 15-29 years old) ( χ2=14.43, 59.62 and 43.23, P all<0.01) . The positive rates of anti-HBs were 51.98%, 68.18% and 58.82% in Han, Manchu and other ethnic group, respectively, with statistically significant differences ( χ2=59.62, P<0.05) . For the people born during 2002-2013 when hepatitis B vaccine was integrated in expanded program of immunization (EPI) , the positive rates of HBs, anti-HBsAg and anti-HBc were 0.29%, 57.65% and 3.38%, respectively. And the positive rates of the three serum markers in different age groups were significantly different ( χ2trend=13.12, 14.43 and 52.58, P all<0.05) . There were 8 modes of HBV markers detected, in which single anti-HBs positive mode and negative mode of 5 indicators were the most common ones with the detection rates of 49.06% and 44.34%, respectively. Conclusions:The positive rate of HBsAg is low among people aged 1-29 years in Hebei province, and the HBsAg prevalence has decreased to less than 1% since HBV vaccine was integrated into EPI. It shows that the national EPI strategy for hepatitis B has achieved good effect.

In 1996, 3,515 susceptible children aged one to 12 years were recruited in a randomized, open trial to assess the efficacy of a live-attenuated HA vaccine. A comprehensive and systematic assessment of long-term persistence of anti-HAV antibodies, as well as protection against infection conferred by vaccine was performed based on this cohort. During the 17-year follow-up, the sero-positive rate and the geometric mean concentrations declined from 94.9% and 131.3 mIU/mL (91.5-188.4mIU/mL) at the peak to 55.6% and 41.1 mIU/mL (95% CI: 27.8-61.0 mIU/mL) respectively, with a similar natural infection rate in both groups. These results suggest that a booster dose is currently not necessary.

Background Diarrhea remains the leading cause of childhood illness in China. Better understanding of burden and etiology of diarrheal diseases is important for development of effective prevention measures. Methods Population-based diarrhea surveillance was conducted in Sanjiang (southern China) year-round and Zhengding (northern China) in autumn/winter. Stool specimens were collected from children < 5 years of age experiencing diarrhea. The TaqMan Array Card (TAC), based on multiplex real-time PCR, was applied to detect multiple enteric microbial agents simultaneously. Results using these methods were compared to those derived from conventional PCR assays. Results During the study period, 6,380 children in Zhengding and 3,581 children in Sanjiang < 5 years of age participated. Three hundred and forty (31.2%) and 279 (22.9%) diarrhea episodes were identified as moderate-to-severe in the two counties, with incidence of 60.4 and 88.3 cases per 1,000 child-years in Zhengding and Sanjiang, respectively. The five most frequently detected bacterial and viral agents in Sanjiang were adenovirus, enterovirus, enteroaggregative Escherichia coli (EAEC), rotavirus, and sapovirus all the year round, while the most common viral agents in Zhengding were rotavirus, followed by astrovirus and adenovirus during the cool season. Compared to conventional PCR assay, the average incremental detection via the TAC method was twofold. Conclusion Our study demonstrated high diversity and prevalence of multiple major bacterial and viral agents, including rotavirus and calicivirus, among children in China. Further studies are needed to define the public health significance of neglected but frequently detected pathogens such as EAEC, enterotoxigenic E. coli, Campylobacter, adenovirus, and enterovirus.

Objective:To evaluate the safety and immune efficacy of 1-dose domestic lyophilized live attenuated varicella vaccine in children aged 1-12 years.Methods:A randomized, double-blind, positive-controlled, non-inferiority clinical trial was conducted in Hebei vaccine clinical research base from October 2018 to December 2020. The subjects were 1 080 children aged 1-12 years, who were assigned in a 1∶1 ratio to receive the test vaccine (Beijing Wantai Biological Pharmacy Enterprise Co., Ltd) and control vaccine (Shanghai Institute of Biological Products Co., Ltd). Adverse reactions within 30 days after vaccination were observed. Before and 30 days after vaccination, 2.5-3.0 mL of venous blood was collected, respectively. The anti-varicella virus antibody was detected by fluorescent antibody to membrane antigen(FAMA), and the positive conversion rate and geometric average titer(GMT) of the antibody were calculated.Results:The antibody positive conversion rate in the experimental group was 96.00%(240/250), which was higher than that of 88.74% in the control group( χ2=9.128, P<0.01). The positive conversion rate(4 times increase) in the experimental group was 92.95%(501/539), which was higher than that of 78.52% in the control group ( χ2=45.915, P<0.01). The GMT in the experimental group was 192.42 (167.92-220.50), which was higher than that of 85.65 (73.29-100.09) in the control group( t=7.683, P < 0.01). The proportion of antibody GMT ≥ 1:128 in the experimental group was 61.97%, which was higher than that of 38.33% in the control group( χ2=60.266, P<0.01). The incidence rates of overall adverse reactions were 24.12%(130/539) in experimental group and 26.48%(143/540) in control group, and the difference was not statistically significant( P>0.05). The common local adverse reactions were redness, swelling and pain. No severe adverse reaction happened in both groups. Conclusions:The immunogenicity and safety of 1-dose domestic lyophilized live attenuated varicella vaccine in children aged 1-12 years are all good.

Rotaviruses (RVs) are the leading cause of acute gastroenteritis in children, while histo-blood group antigens (HBGAs) are believed to be host attachment and susceptibility factors of RVs. A large case–control study nested in a population-based diarrhea surveillance targeting children <5 y of age was performed in rural Hebei province, north China. Saliva and serum samples were collected from all participants to determine HBGA phenotyping, FUT2 mutations, and RV IgG antibody titers. A logistic model was employed to assess the association between host HBGA secretor status and risk of RV infection. Among 235 RV cases and 680 non-diarrhea controls studied, 82.4% of participants were IgG positive by an average age of 77 months. Out of the 235 RV cases, 216 (91.9%) were secretors, whereas the secretor rate was 76.3% in the non-diarrhea controls, resulted in an adjusted OR of 3.0 (95%CI: 1.9–4.7, P < .0001) between the two groups. Our population-based case–control study indicated a strong association between host HBGA secretor status and risk of RV infection in Chinese children. The high prevalence of Lewis-positive secretor status strongly suggests that Chinese children may be genetically susceptible to current co-circulating RV strains, and thus, a universal childhood immunization program against RV disease should be successful in China.

Objective:To understand the immune effect of hepatitis B vaccine in newborns 1-14 years after primary immunization according to a 0-1-6 month vaccination.Methods:Participants who were born in Zhengding county, Hebei between 2002 to 2016, and received a full course of primary vaccination with hepatitis B vaccine, and had no experience with booster vaccination were enrolled. An epidemiological investigation was performed, and 3-5 mL blood samples were collected to detect HBsAg, anti-HBs and anti-HBc. The positive rates of HBsAg, anti-HBs and anti-HBc were calculated to evaluate the immune effect of hepatitis B vaccine.Results:A total of 1 431 participants were included, among whom the anti-HBs positive rate was 68.55% (981/1 431) with a geometric mean concentration (GMC) of 36.65 (95% CI: 31.45-40.42) mIU/mL. The HBsAg and anti-HBc positive rates were 0.21% (3/1 431) and 0.77% (11/1 431) , respectively. The anti-HBs positive rate decreased from over 90% in 1-2 years after primary vaccination to about 50% in 12-14 years later. A significant downtrend with the extension of immunity years was observed in the anti-HBs positive rate ( χ2trend=85.101, P<0.01) . Conclusions:Hepatitis B vaccine in newborns shows a good long-term protective effect 14 years after primary vaccination.

Objective: To assess the immune effect of different types of hepatitis B vaccine (HepB) booster doses 2-32 years after primary immunization, explore the influencing factors, and offer guidance regarding the necessity and timing of boosters. Methods: In total, 1163 participants who were born from 1986 to 2015, received the HepB full-course primary vaccination, were hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) negative, and had hepatitis B surface antibody (anti-HBs) <10 mIU/mL were enrolled. Individuals were randomly divided into two groups and received a booster dose of HepB. Venous blood samples were collected 30 days later and tested for anti-HBs. Results: In total, 595 and 568 individuals received a single dose of HepB (CHO) and HepB (SC), respectively. Venous blood samples were obtained from 1079 vaccinees (CHO: 554, SC: 525). The seroconversion rates were 93.68% (519/554) and 86.67% (455/525) (p < 0.05), with geometric mean concentrations (GMCs) of 426.58 mIU/ml and 223.8 mIU/ml, respectively. This result indicated that BMI, smoking status, vaccine types of booster and prebooster anti-HBs concentration significantly influenced anti-HBs levels. Only BMI, prebooster anti-HBs concentrations and booster types were different between the anti-HBs positive and negative groups. Conclusions: Participants boostered with HepB (CHO) had a relatively higher seroconversion rate than those boostered with HepB (SC). The high seroconversion rates in the two groups suggested that the subjects remained protected despite low circulating antibodies, so there is currently no urgent need for booster immunization. Factors including BMI > 25 and prebooster anti-HBs concentration <2.5 mIU/mL, which contributed to lower responses to a booster dose, might indicate a greater risk of breakthrough infection. (C) 2020 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.

Background: Despite the considerable disease burden caused by the disease, rotavirus vaccine has not been introduced into routine national immunization schedule, and norovirus vaccines are being developed without a comprehensive understanding of gastroenteritis epidemiology. To bridge this knowledge gap, we investigated the disease burden of viral gastroenteritis in rural China. Methods: Between October 2011 and December 2013, population-based surveillance was conducted in Zhengding and Sanjiang counties in China. Stool samples were collected from children <5 years of age with diarrhea. All specimens were tested for rotaviruses, noroviruses, sapoviruses, enteric adenoviruses, and astroviruses. Results: The most common pathogen causing diarrhea was rotavirus (54.7 vs 45.6 cases/1,000 children/year in Zhengding and Sanjiang, respectively), followed by norovirus (28.4 vs 19.3 cases/1,000 children/year in Zhengding and Sanjiang, respectively). The highest incidence of these viruses was observed in children 6-18 months of age. Among the 5 viral pathogens, rotaviruses caused the most severe illness, followed by noroviruses. Conclusion: Rotavirus and norovirus are the 2 most important viral pathogens causing childhood diarrhea in both northern and southern China; they should be the major targets for viral gastroenteritis prevention strategies among children in China. (C) 2019 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.

Objective: Aanalysis the effect of booster one dose of hepatitis B vaccine after 21-32 years of primary immunization in Zhengding Country of Hebei Province. Methods: A total of 322 participants who were born between 1986 and 1996, received a full course of primary vaccination with plasma-derived hepatitis B vaccine (HepB), had no experience with booster vaccination, were HBsAg, anti-HBcnegative, had anti-HBs<10 mIU/ml, completed the booster and had laboratory results were enrolled between August 2017 to February 2018. A simple random method was uesd to randomly assigned 322 subjects to two groups, receiving a booster dose of HepB derived from either Saccharomyces cerevisiae ［HepB (SC), (151 cases)］ or Chinese hamster ovary-derived HepB ［HepB (CHO), (171 cases)］, the dose was 20 μg. Blood samples were collected 30 days after boosting and quantitatively tested for the geometric mean concentration (GMC) of anti-HBs to assess immunological effect. The related influencing factors of GMC and seroconversion rates of anti-HBs were analyzed by multiple linear regression and multivariate logistic regression models. Results: The 266 subjects (82.61%) had anti-HBs≥ 10 mIU/ml, and GMC was (131.63±12.94) mIU/ml.The seroconversion rates of anti-HBs in the anti-HBs<2.5 mIU/ml group and 2.5-10 mIU/ml group were 74.54% (161 cases) and 99.06% (105 cases), respectively (P<0.001).The seroconversion rates of anti-HBs after one dose of HepB (CHO) was higher than that of one dose of HepB (SC), the seroconversion rates were 87.13% (149 cases) and 77.48% (117 cases), respectively (P=0.023). Participants boostered with HepB (CHO) was the factor influencing the effect of strengthening immunization compared with boostered with HepB (SC), and OR (95%CI) was 1.91 (1.02-3.56) (P=0.042).Compared with anti-HBs<2.5 mIU/ml, prebooster anti-HBs was between 2.5 mIU/ml and 10 mIU/ml was the related factor of seroconversion rates of anti-HBs after booster immunization, and OR (95%CI) was 36.15 (4.91-266.02) (P<0.001). Conclusion: Participants boostered withone dose of HepB had a good immune response. Pre-booster anti-HBs concentration and a variety of vaccine were related factors of immune response.

目的 观察新生儿重组乙型肝炎疫苗(CHO细胞)(HepB-CHO)基础免疫后3-6年血清学效果.方法 于2018年选择河北省正定县4个乡2011-2014年出生且已按0-1-6月免疫程序接种3剂次10μg HepB-CHO的儿童,检测免疫后3-6年血清乙肝表面抗体(HBsAb)、乙肝表面抗原(HBsAg)和乙肝核心抗体(HBcAb).结果 观察对象HepB-CHO基础免疫后HBsAb总阳性率为69.3％ (739/1 067),其中2011年、2012年、2013年、2014年出生儿童HBsAb阳性率分别为64.0％(155/242)、68.8％(179/260)、70.1％(213/304)、73.6％(192/261);HBcAb总阳性率为0.19％(2/1 067),其中2011年、2012年、2013年、2014年出生儿童HBcAb阳性率分别为0.00％(0/242)、0.00％(0/260)、0.33％(1/304)、0.38％ (1/261);HBsAg总阳性率为0.00％ (0/1 067).结论 本研究重组HepB-CHO新生儿免疫后3-6年血清学效果良好.

To assess the immune persistence conferred by a Chinese hamster ovary (CHO)-derived hepatitis B vaccine (HepB) 17 to 20 years after primary immunization during early life. Participants born between 1997 and 1999 who received a full course of primary vaccination with HepB (CHO) and who had no experience with booster vaccination were enrolled. Blood samples were required from each participant for measurement of hepatitis B surface antibody (anti-HBs), surface antigen and core antibody levels. For those who possessed an anti-HBs antibody < 10 mIU/mL, a single dose of HepB was administered, and 30 days later, serum specimens were collected to assess the booster effects. A total of 1352 participants were included in this study. Of these, 1007 (74.5%) participants could retain an anti-HBs antibody ≥10 mIU/mL, with a geometric mean concentration (GMC) of 57.4 mIU/mL. HBsAg was detected in six participants, resulting in a HBsAg carrier rate of 0.4% (6/1352). Of those participants with anti-HBs antibodies < 10 mIU/mL, after a challenge dose, 231 (93.1%) presented an anti-HBs antibody ≥10 mIU/mL, with a GMC of 368.7 mIU/mL. A significant increase in the anti-HBs positive rate (≥ 10 mIU/mL) after challenge was observed in participants with anti-HBs antibodies between 2.5 and 10 mIU/mL and participants boosted with HepB (CHO), rather than those with anti-HBs antibodies < 2.5 mIU/mL and those boosted with HepB (SC). Since satisfactory immune protection against HBV infection conferred by primary vaccination administered 17–20 years ago was demonstrated, there is currently no urgent need for booster immunization.

Background: To assess the long-term protection conferred by plasma-derived hepatitis B vaccine at 20–31y after primary immunization during infancy in Chinese rural community. Method: Participants born between 1986 and 1996, who received a full course of primary vaccination with plasma-derived hepatitis B vaccine and had no experience with booster vaccination were enrolled. An epidemiological investigation was performed, and blood samples were collected to detect hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc). The positive rate of HBsAg, anti-HBs, and anti-HBc were calculated to evaluate the long-term protection of the plasma-derived hepatitis B vaccine. Results: A total of 949 participants were enrolled in the final analysis. Six subjects were detected to be HBsAg-positive, resulting in a HBsAg carrier rate of 0.63% (6/949). A total of 468 (52.41%) participants maintained a level of anti-HBs antibody ≥10 mIU/mL, with a GMC of 112.20 mIU/mL (95%CI: 97.72 ~ 128.82 mIU/mL). A significant downtrend was observed in the anti-HBs positive rate (P < .001). The average anti-HBc positive rate was 5.90% (56/949), increased with prolongation of immunization (P < .001). Conclusions: The plasma-derived hepatitis B vaccine maintained satisfactory protection at 20–31 y after primary immunization. These results indicate that a booster dose is not necessary. Further studies on the immune memory induced by the plasma-derived hepatitis B vaccine are needed.

目的 了解河北省成年人群乙肝疫苗接种情况,分析影响乙肝疫苗接种的因素,为乙肝的预防控制提供参考依据.方法 运用多阶段整群系统随机抽样方法,抽取河北省22个县区内的18～60岁常驻居民进行面对面问卷调查.运用单因素分析和多因素logistic回归模型分析影响乙肝疫苗接种率的主要因素.结果 河北省成年人乙肝疫苗接种率为14.70％ (390/2 653).多因素logistic回归分析显示,调查对象的年龄、职业、居住地、文化程度以及暴露于有偿献血、针灸治疗、长期与乙肝表面抗原(HBsAg)阳性成员一起生活是影响成年人乙肝疫苗接种的因素.结论 河北省成年人群乙肝疫苗接种率低,应着重对成年人中较高年龄人群、农民以及高危人群实施科学的乙肝疫苗接种知识的宣传教育.

Background: In recent years, hepatitis A virus (HAV) infection has declined considerably in China, associated with wide deployment of HAV vaccines and improvement in socio-economic indicators. Towards the elimination of HA in the country, we assessed the duration and characteristics of immunity conferred by the widely used, locally manufactured HAV vaccine. Methods: This is a longitudinal cohort study that followed recipients of a live attenuated HAV vaccine 17 years after the initial administration. Blood samples were collected from participants pre- and two-week post-booster HAV vaccine dose. Serum anti-HAV antibody was measured by ELISA method. Memory B and T cells were determined by ELISPOT and Flow Cytometry assays, respectively. Results: A robust anamnestic response was observed two-week post-challenge. Both HAV-specific memory B cell and T cells remained, and responded quickly when re-encountering HAV. The magnitude of recall responses was present, regardless of the status of the serum anti-HAV antibody pre-booster. Conclusions: We demonstrated long-term immunity from the live attenuated HAV vaccine, including antibody persistence and immunological memory. Considering the conditions that make elimination of infectious diseases feasible, following polio, hepatitis A could be targeted for elimination in China. (C) 2017 Elsevier Ltd. All rights reserved.

To understand the distribution of genotyping, as well as evolution of norovirus circulating among children<5yrs., a population-based diarrhea surveillance targeted children<5yrs. was conducted in rural Zhengding County, Hebei Province, China between October 2011 and March 2012. RT-PCR was used to amplify the capsid-encoding region of GI and GII norovirus to identify norovirus infection. All PCR products were sequenced and analyzed for genotyping and constructing phylogenetic tree. Dynamic distribution network was constructed by TempNet to illustrate the genetic relationships at two different time points. Bayesian evolutionary inference techniques were applied by BEAST software to study the norovirus evolution rate. During the 6-month surveillance period, 1091 episodes of diarrhea were reported from 5633 children under 5years of age lived in catchment area. 115 of 1091 stool specimens were detected as norovirus positive (10.54%). Five genotypes based on capsid gene sequences were identified, including GII.2 (11), GII.3 (52), GII.4 (47), GII.6 (4) and GII.7 (1). An identical haplotype of GII.4 circulated between 2006 and 2011 in Hebei Province. A mean rate of 6.29×10−2 nucleotide substitutions/site/year (s/s/y) was obtained for GII.3 viruses in Hebei, while the GII.4 viruses evolved at a mean rate of 3.67×10−2s/s/y. In conclusions, GII.3 (45.22%) and GII. 4(40.87%) are the predominant strain in Hebei Province in the winter season of 2011 and 2012. Different from the current consensus, our study shows that GII.3 noroviruses in Hebei Province evolved at a faster rate than GII.4 viruses.

Objective: To evaluate the long-term efficacy of Chinese hamster ovary (CHO) cell derived hepatitis B vaccine after being used for 14-16 years in country community in Hebei province in China.Method: A cross-sectional investigation was carried out in 3 of 7 randomly selected rural communities in Zhengding County in 2013. The children who were born between 1997 and 1999 and were vaccinated with three doses of CHO-derived hepatitis B vaccine were eligible to participate in the study. Their sera samples were tested for HBV serological markers. For HBsAg positive children, their historical results were compared, in order to see whether these were new infections.Results: Among the 920 participating children, the prevalence of HBsAg, anti-HBs and anti-HBc were 0.65%, 73.15% and 1.20% respectively. The differences between birth-year groups were not significant. When compared with baseline, the vaccine efficacy was 94.2% and the anti-HBs titers of 668 children with sole anti-HBs positivity were 178.8 mIU/ml. By comparing with historical data, no new infection was found in this latest survey. Among 6 mothers of HBsAg positive children, 4 were HBsAg positive, 1 was negative and 1 was unknown.Conclusion: The long-term efficacy of the CHO derived hepatitis vaccine is good and stable for 14-16 years after vaccination. A booster dose seems not necessary. Implementing mother-newborn blocking measures for newborns from HBsAg carrier mothers is urgently needed in the future. (C) 2014 Elsevier Ltd. All rights reserved.