Factors influencing the routine immunization status of children aged 2-3 years in China.

OBJECTIVES: To examine the factors associated with the routine immunization status of children aged 2-3 years in China for gaining a better understanding of the Expanded Program on Immunization and to provide evidence for formulating specific strategies to guide the allocation of health resources. METHODS: We analyzed data from 45095 children aged 2-3 years in the 2013 National Immunization Coverage Survey to identify the sociodemographic and provider-associated factors affecting the full immunization status of children. Univariate and multiple logistic regression analyses were performed. RESULTS: The immunization rate for children aged 2-3 years ranged from 95.9% (diphtheria and tetanus toxoid with pertussis vaccine, 4th dose) to 99.5% (Japanese encephalitis vaccine, 1st dose) and was 93.1% for full immunization. In terms of sociodemographic factors, male children [adjusted OR (AOR): 1.115; 95% confidence interval(CI):1.016-1.222], minority children (AOR: 1.632; 95% CI: 1.457-1.828), children of fathers with less than high school education (AOR: 1.577; 95% CI: 1.195-2.081), those born at home (AOR: 4.655; 95% CI: 3.771-5.746), those who immigrated from an adjacent county (AOR: 2.006; 95% CI: 1.581-2.546), and those living in urban-rural fringe areas (AOR: 1.807; 95% CI: 1.475-2.214) or mountainous areas (AOR: 1.615; 95% CI: 1.437-1.814) had significantly increased odds of not being fully immunized. In terms of provider-associated factors, administration of vaccines at home (AOR: 2.311; 95% CI: 1.316-4.059), household reminders (AOR: 2.292; 95% CI: 1.884-2.789), and travel time to vaccination providers of >40 minutes (AOR: 1.622; 95% CI: 1.309-2.010) were negatively associated with immunization rates. In addition, compared to 3-year-old years, 2-year-old children (AOR: 1.201; 95% CI: 1.094-1.318) were less likely to be fully immunized. CONCLUSIONS: All included factors except maternal education level and distance from home to vaccination providers significantly affected immunization rates. Appropriate reminders and accessibility of immunization services played key roles in improving the immunization status. More attention to high-risk groups identified in this study may reduce the disparities in routine childhood immunization in China.

Enhanced surveillance of acute flaccid paralysis following importation of wild poliovirus in Xinjiang Uygur Autonomous Region, China.

BACKGROUND: After being polio free for more than 10 years, an outbreak occurred in China in 2011 in Xinjiang Uygur Autonomous Region (Xinjiang) following the importation of wild poliovirus (WPV) originating from neighboring Pakistan. METHODS: To strengthen acute flaccid paralysis (AFP) surveillance in Xinjiang, "zero case daily reporting" and retrospective searching of AFP cases were initiated after the confirmation of the WPV outbreak. To pinpoint all the polio cases in time, AFP surveillance system was expanded to include persons of all ages in the entire population in Xinjiang. RESULTS: Totally, 578 AFP cases were reported in 2011 in Xinjiang, including 21 WPV cases, 23 clinical compatible polio cases and 534 non-polio AFP cases. Of the 44 polio cases, 27 (61.4%) cases were reported among adults aged 15-53 years. Strengthening AFP surveillance resulted in an increase in the number of non-polio AFP cases in 2011 (148 children < 15 years) compared with 76 cases < 15 years in 2010. The AFP surveillance system in Xinjiang was sensitive enough to detect polio cases, with the AFP incidence of 3.28/100,000 among children < 15 years of age. CONCLUSIONS: Incorporating adult cases into the AFP surveillance system is of potential value to understand the overall characteristics of the epidemic and to guide emergency responses, especially in countries facing WPV outbreak following long-term polio free status. The AFP surveillance system in Xinjiang was satisfactory despite limitations in biological sample collection.

[Analysis on reported data of immunization monitoring system for category II vaccine in China, 2012].

OBJECTIVE: To analyze the immunization status of category II vaccine in Chinese Mainland in 2012. METHODS: The completeness of report unit by township and county, including 31 provinces (cities, municipalities) and Xinjiang Production and Construction Corps, the number of doses and the number of counties covered for category II vaccine at different areas, average types of category II vaccine by county were analyzed by descriptive epidemiological methods, according to monthly report of vaccination data for category II vaccines by township in 2012 which all of provinces and population were almost covered, through the National Immunization Program(NIP) monitoring information system of China. RESULTS: A total of 29 kinds of category II vaccine with 90 843 530 doses were reported in 2012, and the total average dose was 674.2 per 10 000 people. The report completeness by county and township were 83.32% (29 557/35 472) and 80.01% (396 652/495 756) respectively. The reported doses of rabies vaccine for human use, Haemophilus influenza type b vaccine and influenza vaccine was the top third vaccine, among those for all kinds of category II vaccine, which were 17 027 259, 13 996 206, 11 324 518 respectively, and 126.4, 103.9, 84.1 doses per 10 000 people. In 2773 county units, varicella attenuated live vaccine, influenza vaccine, rabies vaccine for human use were the top three kinds of category II vaccine in terms of the number of county where vaccines have been used in 2012, which were 2442(88.06%), 2415(87.09%), 2366(85.32%) respectively. Guangdong province with 12 266 531 doses was the highest report doses for category II vaccine whereas Qinghai province with 57 767 doses was the lowest number in 2012. Regarding to the average report doses by province, the highest or lowest number was 2425.0 doses per 10 000 people in Shanghai province, and 101.7 doses per 10 000 people in Qinghai province separately. CONCLUSION: Many kinds of category II vaccine with a large amount have been used in China, and there are significant different among areas. Surveillance and management for category II vaccines should be future improved.

Safety of influenza A (H1N1) vaccine in postmarketing surveillance in China.

BACKGROUND: On September 21, 2009, China began administering vaccines, obtained from 10 different manufacturers, against 2009 pandemic influenza A (H1N1) virus infection in priority populations. We aimed to assess the safety of this vaccination program. METHODS: We designed a plan for passive surveillance for adverse events after immunization with the influenza A (H1N1) vaccine. Physicians or vaccination providers were required to report the numbers of vaccinees and all adverse events to their local Center for Disease Control and Prevention (CDC), which then reported the data to the Chinese CDC through the online National Immunization Information System's National Adverse Event Following Immunization Surveillance System. Data were collected through March 21, 2010, and were verified and analyzed by the Chinese CDC. RESULTS: A total of 89.6 million doses of vaccine were administered from September 21, 2009, through March 21, 2010, and 8067 vaccinees reported having an adverse event, for a rate of 90.0 per 1 million doses. The age-specific rates of adverse events ranged from 31.4 per 1 million doses among persons 60 years of age or older to 130.6 per 1 million doses among persons 9 years of age or younger, and the manufacturer-specific rates ranged from 4.6 to 185.4 per 1 million doses. A total of 6552 of the 8067 adverse events (81.2%; rate, 73.1 per 1 million doses) were verified as vaccine reactions; 1083 of the 8067 (13.4%; rate, 12.1 per 1 million doses) were rare and more serious (vs. common, minor events), most of which (1050) were allergic reactions. Eleven cases of the Guillain-Barré syndrome were reported, for a rate of 0.1 per 1 million doses, which is lower than the background rate in China. CONCLUSIONS: No pattern of adverse events that would be of concern was observed after the administration of influenza A (H1N1) vaccine, nor was there evidence of an increased risk of the Guillain-Barré syndrome.

Effect of aluminum hydroxide adjuvant on the immunogenicity of the 2009 pandemic influenza A/H1N1 vaccine: multi-level modeling of data with repeated measures.

OBJECTIVE: To evaluate the effect of the aluminum hydroxide (Al-OH) adjuvant on the 2009 pandemic influenza A/H1N1 (pH1N1) vaccine. METHODS: In a multicenter, double-blind, randomized, placebo-controlled trial, participants received two doses of split-virion formulation containing 15 µg hemagglutinin antigen, with or without aluminum hydroxide (Al-OH). We classified the participants into six age categories (>61 years, 41-60 years, 19-40 years, 13-18 years, 8-12 years, and 3-7 years) and obtained four blood samples from each participant on days 0, 21, 35, and 42 following the first dose of immunization. We assessed vaccine immunogenicity by measuring the geometric mean titer (GMT) of hemagglutination inhibiting antibody. We used a two-level model to evaluate the fixed effect of aluminum Al-OH and other factors, accounting for repeated measures. RESULTS: The predictions of repeated measurement on GMTs of formulations with or without Al-OH, were 80.35 and 112.72, respectively. Al-OH significantly reduced immunogenicity after controlling for time post immunization, age-group and gender. CONCLUSION: The Al-OH adjuvant does not increase but actually reduces the immunogenicity of the split-virion pH1N1 vaccine.

[Progress of childhood immunization information management system in China in 2008].

OBJECTIVE: To evaluate the coverage of childhood immunization information management system (CIIMS) in China (not include HongKong, Macao, and Taiwan) in 2008. METHODS: Analyzing immunization cases and users' file record archives in CIIMS for china in 2008. RESULTS: These data indicated that 87.10% (27/31) of provinces and 30.36% (891/2935) of county level and 26.63% (11,512/43,231) of vaccination points of township level submitted immunization data to an CIIMS in 2008. The rate of implementation of the county > or = 90% are Fujian and Hubei. The rate of implementation of the township > or = 90% are Hubei, Fujian and Hebei. Coverage of eastern areas, middle areas and western areas were 28.91%, 43.20%, and 18.41% by county, 26.15%, 37.69%, and 16.44% by township respectively. The upload permissions against cases is in a total of 15,014 units, and the client software collect a total of 42,956,214 cases of immunization. 44.46% chinese children aged < 6 years old participated in an CIIMS in 2008. The vaccination point of township level submitted 8,793,334 cases to CIIMS, it accounted for 20.47% of client collection cases. CONCLUSION: To achieve the national CIIMS objectives for 2010, the extensive implementation must be promoted, the funding for system-building should be increased, an independent platform of CIIMS must be established, and admission of the issue of data exchange with the local information systems must be accelerated.

[Study on the immunity of diphtheria in children at county level with different 4-vaccine coverage rates based on the results from "National Immunization Program Review" in 2004].

OBJECTIVE: To investigate the immunity level of diphtheria antibody among children living in the areas where different coverage rates of 4-vaccines stratified by results of national immunization program (NIP) reviewed in 2004. METHODS: According to data from 4-vaccine coverage rates of NIP reviewed in 2004, 3 levels could be set. We randomly selected 2 counties at each level and then 10 villages from each county with 42 children involved who were born between 1992 and 2003. ELISA quantitative method was used to test IgG of diphtheria antitoxin. RESULTS: (1) The positive rate of diphtheria antitoxin was only 49.6% with the highest as 78.1% and lowest as 33.0%. There was a significant decreasing trend of this positive rate with the increase of age. The highest (61.2%) fell in the group that were born in 2003 and the lowest (37.6%) was seen among children born in 1992 to 1995. (2) Geometric mean concentrations (GMCs) was only 0.48 IU/ml with a trend of decrease when age was increasing. There was no GMCs peak seen in children who were at the age of boosting, as expected. (3) Positive rates of children born between 2001 and 2003 were lower than 62% while the diphtheria-pertussis-tetanus (DPT) vaccine coverage rates were all higher than 90%. (4) There was no significant difference of diphtheria antitoxin positive rates between children with eligible routine immunization (58.1%) and those were ineligible (59.6%). CONCLUSION: Other than some specific ones, children from most of the investigated counties had a low level of antibody against diphtheria. The coverage rate of DPT vaccine did not necessarily reflect the immunity against diphtheria, suggesting the increase of immunity against diphtheria an urgent task to be taken care of.

[Mechanism of the angiogenic effect of bone marrow stromal cells implantation on acute myocardial infarction].

AIM: To study the mechanism of the therapeutic angiogenesis effect of bone marrow stromal cells (BMSCs) implantation on rat acute myocardial infarction models. METHODS: The rat acute myocardial infarction models were made by coronary artery ligation and divided into 2 groups at random. In the experiment group, twice passaged BMSCs were labeled with BrdU and then implanted into the infarction region of the recipients in 4 weeks. The control group was the model rats received only DMEM injection. In control group, the hearts were harvested on the day 3, 7, 14, 28, 42 and 56. The infarction regions were examined to identify the angiogenesis and the expression of the VEGF and bFGF. In experiment group, the hearts were examined on the day 42 and 56 after AMI (the day 14 and 28 after cells implantation). RESULTS: Viable cells labeled with BrdU could be identified in host hearts. Histologic examination found most donor cells within the infarction region expressed fibroblastic and endothelial phenotype. The transplantation regions had a greater capillary density than the control regions did (14 +/- 4.7/HPF vs 6 +/- 2.4/HPF, P < 0.05). In the control group, the expression of VEGF and bFGF within the infarction regions peaked on day 7, and then decreased over time. In the experiment groups, the expression of bFGF and VEGF on the day 42 and 56 had a higher level than the control group did. CONCLUSION: The expression of VEGF and bFGF is significantly increased after cells therapy during the late phase of AMI. It indicates that BMSCs implantation promoted the angiogenesis is mediated by its differentiation into endothelium and the increased release of VEGF and bFGF.