乙型肝炎疫苗人群免疫研究进展

从1984年,世界卫生组织肝炎专家咨询组及全球计划免疫咨询组就开始强调控制乙型肝炎。主要的方法是对人群进行乙肝疫苗接种,特别是新生儿和学龄前儿童。1995年要求HBsAg携带率达8％的国家要有免疫规划,1997年所有国家要开展乙肝疫苗接种。现将人群免疫研究进展情况综述如下：     

COVID-19疫苗免疫应答及保护效力研究进展

由严重急性呼吸综合征冠状病毒-2(SARS-CoV-2)感染引起的2019冠状病毒疾病(COVID-19)为全球性流行病和公共卫生威胁.人们付出了巨大的努力去认识和治疗COVID-19,更可取的是防止感染及临床疾病形成.COVID-19疫苗包括灭活疫苗、腺病毒载体疫苗、mRNA疫苗和亚单位疫苗接种都可诱导绝大多数受试成...     

乙型肝炎疫苗免疫人群效果观察

为评价乙型肝炎 (乙肝 )疫苗在人群中应用的效果 ,采用多阶段整群系统随机抽样的方法 ,对河南省 13个县市中的 1890个家庭 ,5890人进行乙肝疫苗接种情况的调查。发现接种疫苗者HBsAg阳性率明显降低 ,抗 HBs阳性率明显升高。只接种 1针者无免疫保护作用 ;2岁内接种疫苗效果最好 ;5岁以下儿童中接种率达到 70 %时可使HBsAg阳性率降低到 1%以下。结果说明乙肝疫苗在人群中应用效果明显 ,小年龄接种和全程接种对效果影响显著 ,维持高的接种率才会使相应人群带毒率明显下降。     

在SLE患者中羟氯喹增加甲流疫苗免疫效力

<正>巴西一项研究显示,SLE患者接受免疫抑制治疗可降低甲型H1N1流感疫苗效力,但羟氯喹(CQ)可能会恢复患者的免疫原性。论文1月31日在线发表于《风湿病学》(Rheumatology)杂志。该研究显示,与健康对照相比,泼尼松(PRED)、免疫抑制剂(IS)及PRED+IS治疗组SLE患者注射甲型H1N1流感疫苗后的     

现场麻疹疫苗效力测定的评价

襄樊市于1986~1989年对196份麻苗进行了监测,发现有14个(次)样品不合格。据此采取了相应的措施,取得了较好的效果。4年监测结果,肯定了麻苗效力测定在麻苗免疫中的指导作用,肯定了目前我市冷链设备对接种质量的保证作用。另外,对所测麻苗效价低的原因进行了分析;于不同地区、不同季节对麻苗效力的稳定性影响进行了试验和研究;对部分所测麻苗效价低而HIAb效价反而偏高的原因进行了调查和理论上的探讨。     

基因多态性对疫苗免疫应答影响的研究进展

基因在免疫系统应答过程中扮演着重要的角色,不同的基因位点可能引起疫苗免疫应答率的高低差异。本文对基因多态性与疫苗免疫应答的文献进行综述,旨在探究基因多态性会对疫苗免疫应答产生的影响,从基因水平上探讨个体接种疫苗后产生免疫应答的效果,为个体化免疫发展策略提供科学依据。综述结果显示人类白细胞抗原基因、各类细胞因子及其受体基因、Toll样受体类基因的单核苷酸多态性都会影响疫苗免疫应答。     

人群乙型肝炎疫苗免疫保护效果调查

广州港位于广州市八大区中的五大区 ,既有旧城区和新城区又有郊区 ,其中黄埔区是城乡结合区。掌握该港区人群乙肝疫苗接种情况 ,对了解广州市区具有代表性。为此 ,我们于 1998年健康体检中对该区内的人群乙肝疫苗免疫效果进行调查 ,现报告如下。1　对象和方法1.1　调查对象　接种组为广州港及黄埔地区 0～ 5 9岁的人群在 1998年以前分批、分散按 0、1、6月或 0、1、3月的程序 ,每次接种 5μg乙肝疫苗者的 16 846人 ,对照组为未接种乙肝疫苗的980 4人 ,两组在年龄、性别、职业及有关特征的构成上一致。1.2　调查内容　人群身体健康情况、年龄…     

流行性腮腺炎疫苗的效力分析

目的探讨流行性腮腺炎疫苗的效力。方法选择已接种流腮疫苗但发生流腮爆发疫情的两所学校,使用疫情爆发调查和1∶2非匹配病例对照研究统计疫苗效力。结果叶家琪小学爆发和病例对照研究的疫苗效力分别为78.80%和81.36%,小洲小学爆发和病例对照研究的疫苗效力分别为75.76%和76.60%。结论流腮疫苗能够预防流腮发生。     

不同年龄人群对风疹疫苗的免疫应答研究

作者报告了江苏省在风疹疫苗使用前人群的自然免疫状况，４岁以下年龄组血凝抑制（ＨＩ）抗体阳性率在２５％以下，随着年龄的增长，自然免疫水平增高，１３～２５岁人群阳性率约在８０％左右。接种风疹疫苗１月后，抗体１００％阳转，ＧＭＴ从免前的１３．３３上升至２４３．１６，说明国产ＢＲＤⅡ株风疹减毒活疫苗具有良好的免疫原性。对于免前阳性人群，风疹疫苗接种后抗体亦有显著性上升     

加强对新生儿以外人群乙型肝炎疫苗免疫

在五型病毒性肝炎中,以乙型肝炎(乙肝)对我国人民健康危害最为严重。急性乙肝易发展成慢性,其中一部分可演变为肝硬化和原发性肝细胞癌(肝癌)。因此,接种乙肝疫苗不仅可预防乙肝,也可预防由乙肝病毒(HBV)感染引起的肝硬化和肝癌。由于丁型肝炎病毒必须在HBV感染的基础上才能感染,因此,接种乙肝疫苗还可预防丁型肝炎。自1991年世界卫生组织(WHO)提出将乙肝疫苗纳入     

人类乳头瘤病毒疫苗保护效果Meta分析

目的 评价人类乳头瘤病毒(HPV)疫苗流行病学保护效果.方法 电子检索National Center for Biotechnology Information(NCBI)(《美国国家医学图书馆数据库》)、《Cochrane协作网图书馆》等数据库,将有关接种HPV流行病学保护效果的研究文献进行分析.文献资料使用RevMan5.1软件进行meta分析.结果 符合标准的文献共10篇,均为随机对照试验(RCT).HPV疫苗对相关基因型人类乳头瘤病毒(HPV)引起的尖锐湿疣的疫苗保护效果(VE)为94％(95％ CI:91％～96％),对外阴上皮内瘤样病变Ⅱ/Ⅲ级(VIN2/3)和阴道上皮内瘤样病变(VaIN)的VE为96％(95％CI:86％～99％),对宫颈上皮内瘤样病变Ⅱ/Ⅲ级(CIN2/3),原位癌(AIS)的VE分别为98％(95％ CI:96％-99％)和79％(95％Cl:55％-90％).结论 接种HPV疫苗可以降低尖锐湿疣、VIN2/3、VaIN、CIN2/3和AIS的发病率,具有良好的保护效果.     

疟疾疫苗的研究进展

疟疾疫苗对控制全球疟疾的流行起着相当重要的作用.当前,全球科学家正在研制3种类型的疟疾疫苗:抗红内期原虫疫苗、抗红前期原虫疫苗和传播阻断疫苗.其中一些候选疫苗已进入临床试验,并产生了有意义的结果.此文就这方面研究的主要进展进行综述.     

Beyond efficacy: The full public health impact of vaccines

There is an active discussion in the public health community on how to assess and incorporate, in addition to safety and measures of protective efficacy, the full public health value of preventive vaccines into the evidence-based decision-making process of vaccine licensure and recommendations for public health use. The conference “Beyond efficacy: the full public health impact of vaccines in addition to efficacy measures in trials” held in Annecy, France (June 22–24, 2015) has addressed this issue and provided recommendations on how to better capture the whole public health impact of vaccines.Using key examples, the expert group stressed that we are in the midst of a new paradigm in vaccine evaluation, where all aspects of public health value of vaccines beyond efficacy should be evaluated. To yield a wider scope of vaccine benefits, additional measures such as vaccine preventable disease incidence, overall efficacy and other outcomes such as under-five mortality or non-etiologically confirmed clinical syndromes should be assessed in addition to traditional efficacy or effectiveness measurements. Dynamic modelling and the use of probe studies should also be considered to provide additional insight to the full public health value of a vaccine. The use of burden reduction and conditional licensure of vaccines based on collection of outcome results should be considered by regulatory agencies.     

b型流感嗜血杆菌疫苗流行病学保护效果Meta分析

目的 评价b型流感嗜血杆菌疫苗(Hib)流行病学保护效果.方法 电子检索National Centerfor Biotechnology Information(NCBI,美国国家医学图书馆数据库)和Cochrane协作网图书馆等数据库,将有关接种Hib流行病学保护效果的研究纳入分析.使用RevMan5.1软件进行统计分析.结果 共纳入7篇文献,均为随机对照试验.Hib 对流感嗜血杆菌侵袭性疾病(Hib-D)保护效果(vE)为88％(95％CI:80％ ～93％),对流感嗜血杆菌脑膜炎(HIB-M)的VE为84％(95％CI:74％～93％).结论 接种Hib可以降低因Hib感染所致侵袭性疾病和脑膜炎的发病率,具有良好的保护效果.     

The impact of indirect benefits of vaccination on postlicensure vaccine effectiveness estimates: A scenario analysis

Vaccine efficacy is measured in randomized, prelicensure clinical trials where vaccination typically affords only direct protection to the vaccinated individual. Vaccine effectiveness is measured in postlicensure observational studies where vaccination might provide indirect benefits to a population as a whole in addition to directly protecting the vaccinated individual. The potential discrepancy in effectiveness and efficacy estimates would depend on the postlicensure study design. We developed a mathematical model to assess the impact of indirect benefits on vaccine effectiveness as measured by the common cohort study design under scenarios of homogenous and heterogenous vaccine allocation. We found that under the cohort design, effectiveness estimates equaled efficacy if either the indirect effects were assumed to be negligible or vaccine allocation in the community was homogenous. However, in presence of indirect benefits, effectiveness estimates would be biased upward compared with vaccine efficacy if one of the two sub-populations in the same study had a higher rate of vaccination. Because of indirect effects of vaccination, even in studies where other biases can be eliminated, the presence of distinct sub-populations with varying rates of vaccination can lead to discrepancies between effectiveness and efficacy estimates.     

双歧杆菌基因工程疫苗研究进展

双歧杆菌是人类最早发现的生理性细菌之一,是能在健康人肠道内定植的益生菌.如今,随着分子生物技术的发展,双歧杆菌基因工程疫苗研究日趋受到重视.此文综述了双歧杆菌基因工程疫苗的理论基础、研究进展以及前景.     

Interpreting vaccine efficacy trial results for infection and transmission

Randomized controlled trials (RCTs) have shown high efficacy of multiple vaccines against SARS-CoV-2 disease (COVID-19), and recent studies have shown the vaccines are also effective against infection. Evidence for the effect of each of these vaccines on ability to transmit the virus is also beginning to emerge. We describe an approach to estimate these vaccines’ effects on viral positivity, a prevalence measure which under the reasonable assumption that vaccinated individuals who become infected are no more infectious than unvaccinated individuals forms a lower bound on efficacy against transmission. Specifically, we recommend separate analysis of positive tests triggered by symptoms (usually the primary RCT outcome) and cross-sectional prevalence of positive tests obtained regardless of symptoms. The odds ratio of carriage for vaccine vs. placebo provides an unbiased estimate of vaccine effectiveness against viral positivity, under certain assumptions, and we show through simulations that likely departures from these assumptions will only modestly bias this estimate. Applying this approach to published data from the RCT of the Moderna vaccine, we estimate that one dose of vaccine reduces the potential for transmission by at least 61%, possibly considerably more. We describe how these approaches can be translated into observational studies of vaccine effectiveness.     

不可分型流感嗜血杆菌疫苗研究进展

不可分型流感嗜血杆菌(non-typeable haemophilus influenzae,NTHi)可导致多种感染性疾病,如鼻窦炎、中耳炎、结膜炎、脑膜炎、菌血症等。随着b型流感嗜血杆菌疫苗的应用,NTHi逐渐成为侵袭性及非侵袭型流感嗜血杆菌病的主要病原体,因此目前亟待研究一种安全有效的疫苗来预防NTHi的感染。本文主要针对近年来的一些热点候选抗原及已进行临床试验的疫苗做一综述,为后续的疫苗研制提供依据。     

Estimation of vaccine efficacy against acquisition of pneumococcal carriage

Evaluation of the effect of new conjugate vaccines on nasopharyngeal carriage of Streptococcus pneumoniae (pneumococcus) has been based on simple comparisons of the prevalence of carriage in vaccinees and controls. However, the definition and measurement of vaccine efficacy should be based on knowledge of the actual mechanism of the vaccine's effect. According to current knowledge, conjugate vaccines affect acquisition. We propose a simple-to-use method to measure vaccine efficacy against serotype-specific acquisition that needs only cross-sectional measurements of carriage. We demonstrate the use of the method by application to a data set where it is also possible to estimate efficacy against acquisition from longitudinal measurements.     

Detection of dengue cases by serological testing in a dengue vaccine efficacy trial: Utility for efficacy evaluation and impact of future vaccine introduction

BackgroundDengue diagnosis confirmation and surveillance are widely based on serological assays to detect anti-dengue IgM or IgG antibodies since such tests are affordable/user-friendly. The World Health Organization identified serological based diagnosis as a potential tool to define probable dengue cases in the context of vaccine trials, while acknowledging that this may have to be interpreted with caution.MethodsIn a phase IIb randomized, placebo-controlled trial assessing the efficacy of a tetravalent dengue vaccine (CYD-TDV) in Thai schoolchildren, case definition was based on virological confirmation by either serotype-specific RT-PCRs or by NS1-antigen ELISA (Clinicaltrials.gov NCT00842530). Here, we characterized suspected dengue cases using IgM and IgG ELISA to assess their utility in evaluating probable dengue cases in the context of vaccine efficacy trials, comparing virologically-confirmed and serologically diagnosed dengue in the vaccine and placebo groups. Serologically probable cases were defined as: (1) IgM positive acute- or convalescent-phase samples, or (2) IgG positive acute-phase sample and ≥4-fold IgG increase between acute and convalescent-phase samples.ResultsSerological diagnosis had good sensitivity (97.1%), but low specificity (85.1%) compared to virological confirmation. A high level of false positivity through serology diagnosis particularly in the 2 months post-vaccination was observed, and is most likely related to detection of the immune response to the dengue vaccine. This lack of specificity and bias with vaccination demonstrates the limitation of using IgM and IgG antibody responses to explore vaccine efficacy.ConclusionReliance on serological assessments would lead to a significant number of false positives during routine clinical practice and surveillance following the introduction of the dengue vaccine.