Vaccine Immunization Strategies Research Articles

Preliminary investigation and analysis of nucleotide site variability of nine glycoproteins on varicella-zoster virus envelope, Jilin Province, China, 2010-March 2024

Varicella is endemic worldwide. In China, varicella has not yet been included in the list of legal infectious diseases, nor has a unified national surveillance program been established. And the live attenuated varicella vaccine has not been included in routine immunization. In this study, we analyzed for the first time the varicella epidemiology in Jilin Province in the past 20 years, and the nucleotide site, amino acid site and N-glycosylation site variation of glycoprotein in varicella-zoster virus (VZV) surface 9 in the past 15 years. The results showed that the reported incidence of varicella in Jilin Province in the last 20 years was fluctuating above and below 20/100,000, especially after the epidemic of the COVID-19, and fatal cases appeared in individual years. The genotypic branching of VZV was monitored as Clade 2 in the last 15 years. 9 glycogen nucleotide sites of VZV had different degrees of variability, and the variability had specificity. Therefore, it gives us the idea that in order to reduce the incidence of varicella and herpes zoster, a provincial or even national surveillance program should be introduced as early as possible, and the dynamic monitoring of the variability of the nucleotide sites of VZV should be strengthened at the same time as the vaccine immunization strategy is introduced.

The impact of the implementation of the two-dose varicella vaccine immunization strategy in Quzhou: A retrospective birth cohort study

ABSTRACT Varicella is a vaccine-preventable disease caused by the varicella zoster virus (VZV), but the varicella incidence among children has increased in recent years. This was a retrospective birth cohort study based on the Zhejiang Provincial Immune Information System (ZJIIS) and the China Information System for Disease Control and Prevention (CISDCP) in Quzhou. A total of 1,291 clinically diagnosed varicella cases born from 2009 to 2014 were collected during 2009–2023, which were analyzed the impact of changes in vaccination strategy on the incidence of varicella based on the Cox-proportional hazards model. It was observed that the onset age of varicella shifted to the older age group and later to 9–11 years. After the change to the two-dose varicella vaccination strategy, the population affected by varicella was concentrated among students and received more than one dose of live attenuated varicella vaccine (VarV). Based on the Coxproportional hazards model and adjusting for all covariates, the risk of varicella infection in children decreased after the introduction of the two-dose varicella vaccination strategy (HR = 0.04, 95% CI: 0.03–0.05). Meanwhile, the Kaplan–Meier curves also showed that the hazards were lower after the change in vaccination strategy. It is recommended that two doses of VarV should be included in the national immunization schedule and that full vaccination should be completed approximately four years after the first dose.

A novel and cost-effective real-time RT-PCR targeting 24 nucleotides deletion to differentiate PEDV wild-type and classical attenuated vaccine strains

Porcine Epidemic Diarrhea Virus (PEDV) poses a significant threat to the swine industry, causing severe disease and resulting in substantial economic losses. Despite China’s implementation of a large-scale vaccine immunization strategy in recent years, various strains of PEDV, including classical attenuated vaccine strains, continue to emerge in immunized pig herds. Here, we established a one-step real-time fluorescent reverse transcription PCR (one-step real-time RT-PCR) assay targeting a 24-nucleotide deletion in the ORF1 region of three PEDV classical attenuated vaccine strains, derived from classical strains. This assay effectively distinguishes between PEDV classical attenuated vaccine strains and wild-type strains, and we also explore the causes of this discriminatory target deficiency of this method through phylogenetic and recombination analysis. We found that these three classical attenuated vaccine strains exhibit closer phylogenetic relationships and higher sequence similarity with five cell-adapted strains. Recombination analysis revealed that although recombination is widespread in the PEDV genome, the 24-nucleotide deletion site remains stable without undergoing recombination and can be utilized as a target for identification. Further analysis revealed there are no enzyme cleavage sites near the 24-nucleotide site, suggesting that this deletion may have been lost during the process of culturing these viral strains in cells.The detection method we have established exhibits high specificity and sensitivity to PEDV, without cross-reactivity with other viruses causing diarrheal diseases. A total of 117 swine fecal samples were analyzed using this established one-step real-time reverse transcription PCR assay, indicating the presence of classical attenuated vaccine strains in pig herds in Gansu province, China. Additionally, the designed primer pairs and two probes can be placed in a single reaction tube to differentiate between these two types of strains, effectively reducing detection costs. These findings offer an efficient and cost-effective technological platform for clinical rapid identification testing of both wild-type and classical attenuated vaccine strains of PEDV, as well as for precise investigation of clinical data on natural infections and vaccine immunity in pig herds.

Seroepidemiology of pertussis in Huzhou: A population-based, cross-sectional study.

The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance. This study was designed to understand the seroepidemiological characteristics of pertussis infection in the general population of Huzhou City, evaluate the prevalence infection of pertussis in the population, and offer insights to inform adjustments in pertussis prevention and control strategies. From September to October 2023, a cross-sectional serosurvey was conducted in Huzhou City, involving 1015 permanent residents. Serum samples were collected from the study subjects, and pertussis toxin IgG antibodies (Anti-PT-IgG) were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). The analysis included the geometric mean concentration (GMC) of Anti-PT-IgG, rates of GMC≥40IU/mL, ≥100IU/mL, and <5IU/mL. Stratified comparisons were made based on age, vaccination history, and human categories. Among the 1015 surveyed individuals, the geometric mean concentration (GMC) of Anti-PT-IgG was 10.52 (95% CI: 9.96-11.11) IU/mL, with a recent infection rate of 1.58%, a serum positivity rate of 11.43%, and a proportion with <5IU/mL of 40.49%. Among 357 children with clear vaccination history, susceptibility decreased with an increasing number of vaccine doses (Z = -6.793, P < 0.001). The concentration of Anti-PT-IgG exhibited a significant post-vaccination decline over time (Z = -5.143, P < 0.001). In women of childbearing age, the GMC of Anti-PT-IgG was 7.71 (95% CI: 6.90-8.62) IU/mL, with no significant difference in susceptibility among different age groups (χ2 = 0.545, P = 0.909). The annual pertussis infection rate in individuals aged ≥3 years was 9321 (95%CI: 3336-16039) per 100,000, with peak infection rates in the 20-29, 40-49, and 5-9 age groups at 34363 (95%CI: 6327-66918) per 100,000, 22307.72 (95%CI: 1380-47442) per 100,000, and 18020(95%CI: 1093-37266) per 100,000, respectively. In 2023, the actual pertussis infection rate in the population of Huzhou City was relatively high. Vaccine-induced antibodies exhibit a rapid decay, and the estimated serum infection rate increases rapidly from post-school age, peaking in the 20-29 age group. It is recommended to enhance pertussis monitoring in adolescents and adults and refine vaccine immunization strategies.

Guidelines for diagnosis and management and prevention of pertussis of China (2024 edition)

Pertussis re-emergence is a global public health concern. The reported incidence of pertussis in China from 2018 to 2022 was comparable to that in the late 1980s. In fact, the incidence of pertussis is still significantly underestimated in China, owing to a lack of comprehensive active pertussis surveillance, missed diagnosis of atypical pertussis cases, and the fact that many medical institutions do not perform pertussis laboratory diagnosis. Meanwhile, China is also faced with the clinical issue that Bordetella pertussis is highly resistant to first-line macrolide treatment. To better guide and standardize the clinical diagnosis, treatment, monitoring, prevention and control of pertussis cases in China, a multidisciplinary guideline development group comprised of experts in infectious diseases, epidemiology, immunization planning and guideline methodology proposed 12 clinical issues related to the diagnosis, treatment and prevention, especially vaccine immunization strategies from a practical perspective. Through research question construction, evidence retrieval and synthesis, evidence appraisal and evidence-to-decision discussion, recommendations and implementation suggestions were formulated to provide references for clinical physicians engaged in the diagnosis and management of pertussis, microbiological laboratory professionals, hospital infection control professionals, and public health professionals involved in infectious disease prevention, control and immunization planning.

Analysis of influenza vaccination status and immunization strategy in high-risk population

Influenza is a contagious respiratory disease caused by influenza viruses, and the burden of severe disease is commonly seen in high risk populations. Influenza vaccination is an effective way to prevent influenza and its complications, especially for high risk populations. Although some countries have included influenza vaccine in their national immunization programs, influenza vaccination rates remain low globally in high risk populations. The influenza vaccine in China is still a non-immunization program vaccine that is voluntarily vaccinated at its own expense, and the influenza vaccine immunization strategy is different across the country. There is still a gap between the vaccination rate of the influenza vaccine and that of developed countries. It is an urgent problem to further optimize the whole population immunization strategy of influenza vaccine in China, strengthen the publicity of the whole population immunization strategy of influenza vaccine, and reduce the disease burden of influenza in China.

Dynamic changes in polioviruses identified by environmental surveillance in Guangzhou, 2009-2021.

Polio cases can be missed by acute flaccid paralysis AFP case surveillance alone, emphasizing the importance of environmental surveillance. In this study, to investigate the serotype distribution and epidemiological trends of poliovirus (PV), we characterized PV isolated from domestic sewage in Guangzhou city, Guangdong province, China from 2009 to 2021. A total of 624 sewage samples were collected from the Liede Sewage Treatment Plant, and the positive rates of PV and non-polio enteroviruses were 66.67% (416/624) and 78.37% (489/624), respectively. After sewage sample treatment, each sewage sample was inoculated in six replicate tubes of three cell lines, and 3,370 viruses were isolated during the 13-year surveillance period. Among these, 1086 isolates were identified as PV, including type 1 PV (21.36%), type 2 PV (29.19%), and type 3 PV (49.48%). Based on VP1 sequences, 1057 strains were identified as Sabin-like, 21 strains were high-mutant vaccine, and eight strains were vaccine-derived poliovirus (VDPV). The numbers and serotypes of PV isolates in sewage were influenced by the vaccine switch strategy. After type 2 OPV was removed from the trivalent oral poliovirus vaccine and a bivalent OPV was adopted in May 2016, the last type 2 PV strain was isolated from sewage, with no detection thereafter. Type 3 PV isolates increased significantly and became the dominant serotype. Before and after the second vaccine switch in January 2020, that is, from the first dose of IPV and second-fourth doses of bOPV to the first two doses of IPV and third-fourth doses of bOPV, there was also a statistical difference in PV positivity rates in sewage samples. Seven type 2 VDPVs and one type 3 VDPV were identified in sewage samples in 2009-2021, and a phylogenetic analysis indicated that all VDPVs isolated from ES in Guangdong are newly discovered VDPVs, different from VDPV previously discovered in China, and were classified as ambiguous VDPV. It is noteworthy that no VDPV cases were reported in AFP case surveillance in the same period. In conclusion, continued PV environmental surveillance in Guangzhou since April 2008 has been a useful supplement to AFP case surveillance, providing an important basis for evaluating the effectiveness of vaccine immunization strategies. Environmental surveillance improves early detection, prevention, and control; accordingly, this strategy can curb the circulation of VDPVs and provide a strong laboratory basis for maintaining a polio-free status. This article is protected by copyright. All rights reserved.

Expert recommendations on human papillomavirus vaccine immunization strategies in China

HPV vaccination is the most effective way for preventing the cervical cancer. To respond the WHO calling for cervical cancer elimination, some Chinese provincial governments are launching the Free HPV Vaccination Programs for teenagers. Basing on the current stage of domestic utilization and the global immunization strategies of HPV vaccination, this paper provides a comprehensive review of the key aspects in the process of HPV vaccination, including subjects and priority vaccination population, vaccination dose and time interval, the principal of vaccination replacement, and the vaccination suggestion on special populations, etc. The article above contents and gives the advice on the immunization strategy of HPV vaccination in China.

Evidence of the Efficacy and the Effectiveness of First Generation COVID-19 Vaccines in Clinical Trials and Real-world Studies

More than 300 COVID-19 vaccine candidates have been developed or are currently in development. COVID-19 vaccines on the World Health Organization’s Emergency Use Listing and other COVID-19 vaccine products conditionally approved by national regulatory authorities are already in large-scale use, thus preventing severe illness or death and inducing herd immunity at the population level in the SARS-CoV-2 pandemic. In this review, we systemically assess the efficacy and effectiveness of COVID-19 vaccines in clinical trials or real-world studies, in various populations, including healthy adults, children, older people, pregnant people, people with cancer, and people receiving long-term hemodialysis or solid organ transplantation. In addition, we review available evidence regarding the effectiveness of COVID-19 vaccine immunization strategies in people with a history of SARS-CoV-2 infection, and the enhanced effectiveness conferred by various booster immunizations. We also discuss knowledge gaps in the persistence and spectrum of vaccine protection of currently available COVID-19 vaccines.

2011-2019年中国B型流感季节性、年龄特征和疫苗匹配度分析

Objective: To analyze the seasonality, age distribution of influenza B cases and matching degree of influenza B vaccine in China from 2011 to 2019, and provide evidences for the future surveillance, estimation of disease burden of influenza B, application of quadrivalent vaccines, and development of vaccine strategies. Methods: The epidemiological and virological surveillance data of influenza B from week 14 of 2011 to week 13 of 2019 obtained from National Influenza Surveillance Network were used to draw hot spot maps and conduct descriptive statistics to analyze the seasonality and age distribution of influenza B cases. The published antigenicity analysis results from the China Weekly Influenza Report were used to analyze the matching degree between the trivalent vaccine strain and the circulating influenza B strains. Results: From 2011 to 2019, the incidence of influenza B showed obvious seasonal characteristics, and influenza B virus co-circulated with influenza A virus in six winter-spring seasons, and influenza B virus/Victoria and Yamagata lineages circulated alternately. In some southern provinces, two lineages co-circulated in some southern areas in certain years. The age distribution of influenza B cases was double-peaked, and both lineages had the highest positive rate in age-group 5-15 years, with peaks at age of 10 years; B/Victoria virus had a sub-peak in age-group 25-35 years; B/Yamagata virus had a sub-peak in age-group 55-65 years. Trivalent influenza vaccine strain and influenza B epidemic strains mismatched in 2015-2016 and 2017-2018 seasons, matched in 2011-2012, 2012-2013, 2013-2014, 2014-2015 and 2016-2017 seasons, and moderately matched in 2018-2019 season, but reactivity was low. Conclusions: Influenza B mainly occurred in winter-spring season in China, and its intensity was lower than that of influenza A. There was a difference in the age distribution of the cases among different virus strains. Trivalent influenza vaccine strains and influenza B epidemic strains mismatched in several seasons. It is crucial to conduct continuous surveillance of influenza B and disease burden evaluation, improve vaccine immunization strategy, increase influenza vaccination rate to reduce the harm of influenza B in high-risk groups.

Surveillance of immunization effectiveness and titer of type Ⅰ and type Ⅲ polio vaccine in Beijing before and after the adjustment of immunization strategy in 2012-2018

Objective: To analyze the changing trend of polio vaccine immunization effectiveness and vaccine titer in Beijing in 2012, 2014, 2016 and 2018 before and after the adjustment of polio vaccine immunization program strategy. Methods: According to the convenient sampling method,the vaccination clinics of Chaoyang and Yanqing Districts in 2012, Fengtai and Daxing Districts in 2014, Tongzhou and Pinggu Districts in 2016, Dongcheng and Shunyi Districts in 2018 were selected as monitoring points. A total of 292 children were selected 4-8 weeks after the completion of 3 doses polio vaccine basic immunization which were 3 doses of trivalent oral poliovirus vaccine（tOPV）schedule before the strategy adjustment in 2012-2014 and 1 dose of inactivated poliovirus vaccine (IPV) following 2 doses of bivalent oral poliovirus vaccine (bOPV) sequential schedule after the adjustment in 2016-2018. About 1.0 ml blood samples were collected to detect type Ⅰ and Ⅲ neutralizing poliovirus antibody. A total of 9 oral poliovirus vaccines (8 vaccines in 2012) were selected from different sources of vaccine storage every year to test the vaccine titer using random number method. Results: The [M（P25，P75）] age of 292 children was 5 (5, 6) months, and the ratio of male to female was 1.04 (149/143). In 2012, 2014, 2016 and 2018, 66,72,68 and 86 children were investigated respectively. After basic immunization, antibody positive rates for type Ⅰ and Ⅲ poliovirus were 100%, except 98.61% (71) for type Ⅰ poliovirus in 2014. The neutralizing antibody titer of type Ⅰ and Ⅲ poliovirus was higher in 2016 and 2018 than that in 2012 and 2014 (P<0.001). The average titer of tOPV were (6.05±0.15) and (6.16±0.12) lgCCID50 per dose in 2012 and 2014. The average titer of bOPV were (6.88±0.21) and (6.26±0.14) lgCCID50 per 100 μl in 2016 and 2018 (P<0.001). Conclusion: Before and after the adjustment of polio vaccine immunization strategy in Beijing, the basic immunization success rate of the IPV-bOPV sequential immunization schedule was good as well as full tOPV schedule. The level of polio antibody produced by the IPV-bOPV sequential immunization schedule was higher. After adjustment, bOPV titer in 2016 was significantly higher than those before adjustment, while bOPV titer decreased significantly in 2018.

Rotavirus gastroenteritis and its vaccination

Rotaviruses infection is one of the main causes of diarrhea among infants and children in the world, resulting in rotavirus gastroenteritis, which is very harmful and has caused a huge disease burden and no specific drug treatment. This paper reviews the rotavirus etiology, epidemiological characteristics, disease burden of rotavirus gastroenteritis and rotavirus vaccines. RV in group A is the main cause of acute gastroenteritis in infants, people at all ages are generally susceptible to RV, 3 to 24 months infants have the most severe symptoms of diarrhea, RVGE epidemic is seasonal and peaks in winter, increasing RV vaccination can reduce the incidence and mortality of rotavirus diarrhea in infants to reduce the burden of corresponding disease. This article focuses on RV vaccines currently in use and their effect on preventing RV infection, and put forward thoughts and suggestions on technical issues related to the application of RV vaccine in China. Provide support for improving the RV vaccine immunization strategy and Chinese-specific immunization strategy for eventually incorporating RV vaccine into the national child immunization program.

Rapid differentiation of PEDV wild-type strains and classical attenuated vaccine strains by fluorescent probe-based reverse transcription recombinase polymerase amplification assay

BackgroundPorcine epidemic diarrhea virus (PEDV), an intestinal coronavirus that causes acute diarrhea and high mortality in suckling piglets, can result in high economic losses in the swine industry. In recent years, despite the use of China’s current vaccine immunization strategy, multiple types of PEDV strains were still found in immunized swine herds. Our research aims to explore a new rapid differentiation method to distinguish the different types of PEDV strains and assess the safety evaluation of classical attenuated vaccine strains in swine herds.ResultsIn the study, a differential one-step quantitative real-time fluorescent reverse transcription recombinase polymerase amplification (real-time RT-RPA) method based on the PEDV universal real-time RT-RPA assay was established according to the ORF1 deletion sequences of three classical attenuated vaccine strains (PEDV attenuated vaccine KC189944, attenuated CV777 and DR13) and five Vero cell-adapted isolates (JS2008, SDM, SQ2014, SC1402, HLJBY), which could effectively differentiate PEDV classical attenuated vaccine strains from wild-type strains (PEDV classical wild strains and variant strains). The detection limits of PEDV RNA in the both PEDV real-time RT-RPA assays were 300 copies within 20 min at 39 °C, and the detection limits of classical attenuated vaccine strain CV777, Vero-cell-adapted isolate JS2008, and PEDV wild-type strain DX were 100.5 TCID50/100 μL, 101.1 TCID50/100 μL, and 101.2 TCID50/100 μL, respectively. Both assays were highly specific for PEDV, showing no cross-reactivity with other enteral viruses.ConclusionThis RPA method we developed is simple, time-effective, and safe and provides a reliable technical tool for the differential diagnosis and clinical epidemic surveillance of PEDV classical attenuated vaccine strains and wild-type strains.

Investigation and analysis of antibody levels of hepatitis A among children before and after implementing the Expanded National Immunization Program in China

ObjectiveTo analyze changes of hepatitis A antibody levels and immunization coverage of HAV vaccine among children before and after implementing the Expanded National Immunization Program in five counties of China, and to provide evidence for developing hepatitis A vaccine immunization strategies. Methods449 children born in 2001, 2005 and 2009 were selected from five counties for an immunization coverage and a sero-prevalence survey of hepatitis A. The chemiluminescence microparticle immunoassays (CMIA) were used to detect hepatitis A IgG antibody and analyzed the factors which influenced the immunization coverage and positive rates. ResultsAmong 449 subjects of children born in 2001, 2005 and 2009, the immunization coverage were 53.02%, 78.52% and 99.34% (χ2 = 91.285, P < 0.001). The positivity rates of hepatitis A IgG antibody were 61.07%, 81.21%, 95.36% (χ2 = 54.198, P < 0.001), respectively. The immunization coverage and positivity rate significantly increased with the delay of birth year. Children accepting different doses of HA vaccines are significantly different in positive rates of HA antibody, while there are no significant differences of different genders, years of birth, residence types, or types of registered permanent residence in different regions. The positivity rate increased significantly with administration of hepatitis A vaccine and shorter intervals between sample collection and HAV immunization. ConclusionsAfter the Expanded National Immunization Program was implemented, hepatitis A antibody levels were significantly increased in five counties, which indicates a successful result of EPI.

Prevalence of hepatitis A antibody among population covered by different hepatitis A immunization strategies in Shandong Province, 2015, China

Objective: To evaluate prevalence of hepatitis A antibody (anti-HAV IgG) among population covered by different hepatitis A vaccine immunization strategies in Shandong Province in 2015. Methods: In October 2015, according to the geographical location of Shandong Province, the stratified random sampling method was used to stratify the 17 municipal distrcts, and the random number table method was used for sampling, First, two eastern cites (Qingdao, Rizhao), two western cities (Liaocheng, Zaozhuang) and three central cities (Jinan, Zibo and Laiwu) were selected; secondly, one county was drawn from each city. Finally, the participants were divided into five age groups including ≤7 years (age group covered by free hepatitis A vaccination strategy), 8-11 years (age group who receive hepatitis A vaccination at their own charge), 12-24 years (age group covered by catch-up vaccination of hepatitis A), 25-34 years (age group born before hepatitis A vaccine was used) and ≥35 years (age group born before hepatitis A vaccine was used). After all the paticipants or their guardians asked and registered basic information such as age, gender, home address, blood samples were collected from them and anti-HAV IgG was detected by ELISA method. The positive rate of anti-HAV IgG and 95%CI were calculated. Results: A total of 1 654 participants were involved in the final analysis, including 856 males (51.75%) and 798 females (48.25%) whose mean age was (13.44±13.06) years. The crude positive rate of anti-HAV IgG was 91.41% (1 512/1 654, 95%CI: 89.96%-92.72%) and the age-adjusted rate was 90.93% (95%CI: 90.92%-90.94%). The positive rates of anti-HAV IgG was at the highest level in the age group of ≤7 years (95.90%, 95%CI: 95.88%-95.91%) and was at the lowest level in the age group of 25-34 years (83.23%, 95%CI: 83.21%-83.25%). The age-specific positive rates of anti-HAV IgG in eastern areas (96.79%, 95%CI: 96.78%-96.80%) were higher than those in both middle areas (86.66%, 95%CI: 86.65%-86.67%) and western areas (91.96%, 95%CI: 91.95%-91.97%). Conclusion: The positive rate of anti-HAV IgG was high among the general population in Shandong Province, but relatively low among young and middle-aged adults. Besides the routine immunization of hepatitis A among the children, more efforts should be taken for the prevention and control of hepatitis A among young and middle-aged adults in Shandong Province, especially in central and western areas.

Identification and Prioritization of the Economic Impacts of Vaccines.

Understanding the most important economic impacts of vaccines can provide relevant information to stakeholders when selecting vaccine immunization strategies from a broader perspective. This study was therefore designed to first identify economic impacts to vaccinated individuals and, second, assess the relative importance of these economic impacts. A four-step approach was used, including a review of the literature, a pilot study, and expert consultation. As a fourth step, a survey utilizing a best-worst scaling was conducted among 26 different stakeholders to assess the relative importance of the identified economic impacts. In each of the 15 choice tasks, participants were asked to choose the most important and the least important economic impact from a set of four from the master list. We identified 23 economic impacts relevant for vaccine introduction. Four domains were identified, namely, health related benefits to vaccinated individuals, short- and long-term productivity gains, community or health systems externalities, and broader economic indicators. The first domain was seen as especially important with mortality, health care expenditure, and morbidity ranking in the top three overall. In conclusion, our study suggests that domain A “health related benefits to vaccinated individuals” are valued as more important than the other economic impacts.

Effect evaluation of a 2 dose varicella vaccine immunization strategy implemented to control outbreaks in school and kindergarten settings

To evaluate the effect of outbreaks control in school settings after a 2 dose varicella vaccine immunization strategy implemented in Beijing. Epidemiological data of varicella outbreaks in school and kindergarten settings, which were reported by all 16 districts (county) during 2007-2013 according to the technical management norms of Beijing, was collected. The first dose and second dose varicella vaccine coverage rate of eligible children after the 2 dose varicella vaccine immunization strategy implementation were estimated through BJIIMS. Based on above we analyzed the changes of outbreak quantity, case quantity and the distribution characteristics between the pre-adjustment era (2007-2011 years) and late adjustment era (2013) of the 2 dose immunization strategy. In pre-adjustment era (2007-2011 years), an average of 74 (95% CI: 60-89) outbreaks was reported and 964 (95% CI: 812-1 116) cases were involved per year. In late adjustment era (2013): Outbreaks (35) declined 52.7%, involved cases (371) declined 61.5%; Outbreaks epidemic duration shortened from 22 days of pre-adjustment era to 18 days; Outbreaks involved 10-24 cases declined 64.7% (from 34 to 12); Outbreaks involved ≥ 25 cases declined 71.4% (from 7 to 2); Outbreaks of different school type as well as different regions without exception declined dramatically. Cumulative one-dose vaccine coverage in children of 2-6 yr of age was 89.6% (812 859/907 579), and cumulative second-dose vaccine coverage in children of 4-7 yr of age was 44.3% (289 764/647 732). Implementation of a 2 dose varicella vaccine immunization strategy effectively controlled outbreaks in school and kindergarten settings.

A population-based study examining hepatitis B virus infection and immunization rates in Northwest China.

Background and AimCurrent baseline data regarding the prevalence of hepatitis B virus (HBV) infections and the immune status in hyperendemic areas is necessary in evaluating the effectiveness of ongoing HBV prevention and control programs in northwest China. This study aims to determine the prevalence of chronic HBV infections, past exposure rates, and immune response profiles in Wuwei City, northwest China in 2010.MethodsCross-sectional household survey representative of the Wuwei City population. 28,579 participants were interviewed in the seroepidemiological survey ≥1 year of age. House to house screening was conducted using a standard questionnaire. All serum samples were screened by enzyme-linked immunoassays for the presence of hepatitis B surface antigen, antibodies against HBV surface antigen, and antibodies to the hepatitis B core antigen.ResultsAmong individuals ≥1 year of age, 7.2% (95%CI: 6.3–8.1%) had chronic HBV infections, 43.9% (CI: 40.4–47.4%) had been exposed to HBV, and 23.49% (CI: 21.6–25.3%) had vaccine-induced immunity. Multi-factor weighted logistic regression analysis showed that having household contact with HBV carriers (OR = 2.6, 95%CI: 2.3–3.0) and beauty treatments in public places (OR = 1.2, 95%CI: 1.1–1.3) were the risk factors of HBV infection in whole population. Having household contact with HBV carriers (OR = 3.8, 95% CI: 2.2–6.5) and lack of hepatitis vaccination (OR = 2.0, 95% CI: 1.4–3.3) were the risk factors for HBV infection in children aged 1–14 years.ConclusionsHepatitis B infection remains a serious public health problem in northwest China. Having household contact with HBV carriers and beauty treatments in public places represented HBV infection risk factors. Hepatitis B vaccine immunization strategies need further improvement, particularly by targeting the immunization of rural migrant workers.

Seroepidemiologic investigation and analysis of the hepatitis B virus in suining of Sichuan.

Objective To understand the situation of the hepatitis B virus infection in Suining,Sichuan, and to evaluate the results of promoting the hepatitis B vaccine immunization strategy in the neonatal after 1992. Methods A multi-stage stratified random sampling method was adopted, and selected the counties according to administrative region and the economic level. A township (street offices) was randomly selected from each county, in each township selected randomly a village. The family as the unit carried out a questionnaire for 1-59 year old group, and collected blood to detect the HBsAg,anti-HBs and anti-HBc by ELISA. Results A total of 1468 human serum were collected for detect; The positive rate of HBsAg among the crowd was 14.78%, the positive rate of anti-HBs was 39.17%, the infection rate of HBV was 72.68%. HBsAg positive rate of the upper age group was 30 to 34-year-old group (27.59%) and the lowest was 0-4-year-old group (2. 06% ); HBV infection rate was the highest 55-59-year-old group (93.13%) and the lowest was 5-9 year-old group (44. 2%), there were differences in the sex, age,occupation and geographic prevalence rate of HBV infection signs. Conclusion In Suining, Sichuan region, people HBV infection was high, the crowd HBsAg-positive rate was still higher than the national average, but the epidemiological characteristics of hepatitis B among the crowd had changed, to promote the use of hepatitis B vaccine had dramatically reduced the target population ( ≤ 14 year-olds) in HBsAgpositive rate and HBV infection. Key words: Hepatitis B; Seroepidemiologic studies

Hepatitis A Vaccine Recommendations

Since licensure in 1995 of a hepatitis A vaccine, the Centers for Disease Control and Prevention and the American Academy of Pediatrics have been implementing an incremental hepatitis A immunization strategy for children. In 1996, children living in populations with the highest rates of disease were targeted for immunization, and in 1999 the program was expanded to immunization of children 2 years and older living in states and counties with rates of hepatitis A that historically have been higher than the national average. The 1999 program has been successful; the current rate of hepatitis A is the lowest ever reported in the United States. Regional, ethnic, and racial differences in the incidence of hepatitis A have been eliminated. The incidence of hepatitis A in adults in immunizing states has decreased significantly, suggesting a strong herd-immunity effect associated with immunization. In 2005, the US Food and Drug Administration changed the youngest approved age of administration of hepatitis A vaccine from 24 to 12 months of age, which facilitated incorporation of the vaccine into the recommended childhood immunization schedule. As the next step in the implementation of the incremental vaccine immunization strategy, the American Academy of Pediatrics now recommends routine administration of a Food and Drug Administration-licensed hepatitis A vaccine to all children 12 to 23 months of age in all states according to a Centers for Disease Control and Prevention-approved immunization schedule. Available data suggest that hepatitis A vaccine can be coadministered with other childhood vaccines without decreasing immunogenicity. Hepatitis A vaccines have proven to be extremely safe. In prelicensure clinical trials of both Havrix (GlaxoSmithKline, Rixensart, Belgium) and Vaqta (Merck & Co Inc, Whitehouse Station, NJ), adverse events were uncommon and mild when they occurred, with resolution typically in less than 1 day. Hepatitis A vaccine is contraindicated in people with a history of severe allergic reaction to a previous dose of hepatitis A vaccine or to a vaccine component. Because the hepatitis A vaccine is an inactivated product, no special precautions are needed for administration to people who are immunocompromised. No data exist about administration of the hepatitis A vaccine to pregnant women, but because it is not a live vaccine, the risk to mother and fetus should be extremely low to nonexistent.