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.

A 2024 cross-sectional survey in Zhengding County, Hebei, evaluated the 26-year protective efficacy of the Chinese hamster ovary (CHO) cell-derived hepatitis B vaccine (CHO-HepB) and 6.5-year anamnestic response to booster vaccination. Cohort I comprised 178 participants born 1997 and 1999 who had received the standard three-dose series at birth and no subsequent booster. Their mean interval since vaccination was 25.7 years. HBsAg, anti-HBc, and anti-HBs positivity rates were 0.56 % (95 % CI: 0-1.66 %), 1.12 % (95 % CI, 0-2.67 %) and 64.61 % (95 % CI, 57.88-71.34 %), respectively. Among 115 positive individuals, the geometric mean concentration (GMC) was 84.93 mIU/mL (95 % CI, 65.99-109.31). Against a historical local HBsAg prevalence of 11.3 %, the estimated vaccine protection rate was approximately 95.0 %. Serial surveys of the same cohort conducted in 2005, 2009, 2013, 2017, and 2024 revealed no significant increase in HBsAg or anti-HBc positivity over 7-26 years post-vaccination (both P > 0.05), whereas anti-HBs positivity declined significantly (P < 0.05). Cohort II included 97 individuals who received a booster in 2018. After 6.5 years, none were HBsAg or anti-HBc-negative; however, anti-HBs positivity fell from 87.6 % to 51.5 %, and GMCs declined accordingly. In conclusion, CHO-HepB confers durable protection for at least 26 years, with no new infections or carriers observed despite waning anti-HBs levels. Routine booster does may be unnecessary for the general population, yet targeted boosting could help sustain herd immunity and avert future outbreaks, particularly in high-risk populations. Continued emphasis on preventing mother-to-child transmission remains essential for hepatitis B control.

Rotavirus remains a major cause of diarrhea among 5-y-old children, and vaccination is currently the most effective and economical measure. We conducted a randomized, double-blind, placebo-controlled phase II clinical trial designed to determine the dosage, immunogenicity, and safety profile of a novel hexavalent rotavirus vaccine. In total, 480 eligible healthy infants, who were 6-12 weeks of age at the time of randomization were randomly allocated (1:1:1) to receive 105.5 focus-forming unit (FFU) or 106.5FFU of vaccine or placebo on a 0, 28 and 56-d schedule. Blood samples were collected 28 d after the third dose to assess rotavirus immunoglobulin A (IgA) antibody levels. Adverse events (AEs) up to 28 d after each dose and serious adverse events (SAEs) up to 6 months after the third dose were recorded as safety measurements. The anti-rotavirus IgA seroconversion rate of the vaccine groups reached more than 70.00%, ranging from 74.63% to 76.87%. The postdose 3 (PD3) geometric mean concentrations (GMCs) of anti-rotavirus IgA among vaccine recipients ranged from 76.97 U/ml to 84.46 U/ml. At least one solicited AE was recorded in 114 infants (71.25%) in the high-dose vaccine group, 106 infants (66.25%) in the low-dose vaccine group and 104 infants (65.00%) in the placebo group. The most frequently solicited AE was fever. The novel oral hexavalent rotavirus vaccine was safe and immunogenic in infants support the conclusion to advance the candidate vaccine for phase 3 efficacy trials.

Background Norovirus is a leading cause of acute gastroenteritis among children. Previous studies based on symptomatic infections indicated that mutations, rather than recombination drove the evolution of the norovirus ORF2. These characteristics were found in hospital-based symptomatic infections, whereas, asymptomatic infections are frequent and contribute significantly to transmission. Methods We conducted the first norovirus molecular epidemiology analysis covering both symptomatic and asymptomatic infections derived from a birth cohort study in the northern China. Results During the study, 14 symptomatic and 20 asymptomatic norovirus infections were detected in 32 infants. Out of the 14 strains that caused symptomatic infections, 12 strains were identified as GII.3[P12], and others were GII.4[P31]. Conversely, 17 asymptomatic infections were caused by GII.4[P31], two by GII.2[P16], and one by GII.4[P16]. Regardless of symptomatic and asymptomatic infections, the mutations were detected frequently in the ORF2 region, and almost all recombination were identified in the RdRp-ORF2 region. The majority of the mutations were located around the predefined epitope regions of P2 subdomain indicating a potential for immune evasion. Conclusion The role of symptomatic as well as asymptomatic infections in the evolution of norovirus needs to be evaluated continuously.

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.

ABSTRACT Background Rotavirus infections, prevalent in human populations, are caused mostly by group A viruses. Immunization against rotaviruses in infancy is currently the most effective and economical strategy to prevent rotavirus infection. This study evaluated the safety of a novel hexavalent rotavirus vaccine and analyzed its dose and immunogenicity. Methods This randomized, double-blinded, placebo-controlled phase I clinical trial enrolled healthy adults, toddlers, and infants in Zhengding County, Hebei Province, northern China. 40 adults and 40 children were assigned in a 2:1:1 ratio to receive one vaccine dose, placebo 1, and placebo 2, respectively. 120 6–12 week old infants were assigned equivalently into 3 groups. The infants in each group were assigned in a 2:1:1 ratio to receive three doses of vaccine, placebo 1, and placebo 2, at a 28-day interval. Adverse events (AEs) until 28 days after each dose and serious adverse events (SAEs) until 6 months after the third dose were reported. Virus shedding until 14 days after each dose in infants was tested. Geometric mean concentrations (GMCs) and seroconversion rates were measured for anti-rotavirus IgA by using an enzyme-linked immunosorbent assay (ELISA). Results The solicited and unsolicited AE frequencies and laboratory indexes were similar among the treatment groups. No vaccine-related SAEs were reported. The average percentage of rotavirus vaccine shedding in the infant vaccine groups was 5.00%. The post-3rd dose anti-rotavirus IgA antibody geometric mean concentrations (GMC) and seroconversion rate were higher in the vaccine groups than in the placebo groups. Conclusions The novel oral hexavalent rotavirus vaccine was generally well-tolerated in all adults, toddlers and infants, and the vaccine was immunogenic in infants.

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.

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 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.

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.

A universal rotavirus (RV) immunization program is a potentially cost-effective measure for preventing RV infection in China. However, the efficacy of the only licensed RV vaccine (Lanzhou lamb rotavirus vaccine, LLR), which is made by a domestic manufacturer, has not been proven by a properly designed clinical trial. In October 2011 to March 2012, to measure the potential protection provided by LLR, a case-control study nested in a population-based active diarrhea surveillance study of children <5 years of age was conducted in rural Zhengding county. During the study period, 308 episodes of diarrhea were identified as being caused by RV infection, resulting in an incidence rate of 48.0/1000 people/year. The predominant RV serotype was G3 (61.5%), followed by G1 (15.2%), and G9 (6.5%). Overall, a protection of 35.0% (95% confidence interval (CI), 13.0%-52.0%) was identified, and higher protection was found among moderate RV gastroenteritis cases caused by the serotype G3 (52.0% 95% CI: 2.0%-76.1%). A concurrently conducted case-control study comparing non-RV viral diarrheal cases with non-diarrheal controls in the same population found that the RV vaccine offered no protection against non-RV diarrhea. Even under a less ideal immunization schedule, the oral LLR conferred a certain level of protection against RV gastroenteritis. However, further studies are needed to understand the full characteristics of the LLR, including its efficacy when administered following the optimal regimen, the potential risk of inducing intussusception, and the direct and indirect protective effects of LLR.

Objective: To study the epidemiological patterns of hepatitis A, and immunity of entire population in Shijiazhuang prefecture, Hebei province, a former hyper-endemic area in north China.Methods: Cross-sectional, seroprevalence surveys with two-stage cluster sampling were conducted among population older than 2-year between 1992 and 2011. During the 2011 serological survey, blood samples from infants <18 months without hepatitis A immunization history were also collected to determine maternal anti-HAV antibody. Serum samples were tested for anti-HAV antibody by domestic reagent or Abbott reagent Viral hepatitis incidence rates and gross domestic product data were derived from local governmental statistics.Results: Concomitant with the reduction of reported hepatitis A cases between 1992 and 1996 was a significant decline of HAV infections. The average prevalence decreased from 93.6% to 41.9%, and the average age at new infection was postponed from infancy to adolescence. This was attributed to improved socio-economic conditions. With intensive vaccination, a return of new seroconversion rate and seroprevalence was observed. A well fitted exponential regression equation (R-2 = 0.96, p < 0.0001) modeled that the maternal antibody would wane to <20 mIU/mL at 13 months.Conclusion: Benefiting from the booming economy, rapid improvement in sanitation, safe water supply, and implementation of hepatitis A vaccines, the epidemiological pattern of hepatitis A moved from high to intermediate endemicity in Shijiazhuang. Policy makers should be aware of the waning of immunity in entire population, and adapt immunization strategy timely, to ensure a lifelong protection against hepatitis A virus. (C) 2014 Elsevier Ltd. All rights reserved.

Objective To study the HBeAg spontaneous seroconversion among chronic HBV infection.Methods A chronic HBV infection cohort with 172 HBsAg/HBeAg positive carriers was set up through the cross-sectional serological survey in 8 villages of Zhengding county,Hebei province in 1999,2005 and 2006.Serum specimens were collected from all carriers during the follow-up at 2010 and 2012,and were tested for anti-HBs,HBsAg,anti-HBe,HBeAg,HBV DNA,as well as ALT.Results Loss of HBeAg were detected from 32 carriers,the annual rate was 2％ (95％ CI:1.4％-2.8％).Of these,HBeAg seroconversion occurred in 26 carriers,the annual spontaneous HBeAg seroconversion rate was 1.6％ (95％CI:1.1％-2.4％).Conclusion Spontaneous HBeAg seroconversion could be observed in rare cases among chronic HBV carriers,coming along with the significant decrease of HBV DNA and HBsAg level.