上海市2014-2020年流感发病强度的变化情况

目的 评估上海市2014-2020年流感监测网络的运行情况以及流感发病强度的变化。方法 基于上海市2014年1月1日至2020年12月31日的流感监测数据,对哨点医院流感样病例(ILI)缺报漏报和ILI标本采集情况进行评价,计算ILI就诊百分比(ILI%)、流感病毒检出阳性率和流感发病率,利用季节性自回归移动平均模型构建"反事实"情况下2020年流感发病强度的基线,以定量估计上海市2020年流感发病强度的相对变化。结果 2020年上海市ILI缺报漏报情况评价得分和ILI标本采集情况评价得分<5分的医院占比分别为9.68%和21.05%。上海市2014-2019年和2020年的ILI%分别为1.51%(95%CI:1.50%~1.51%)和2.31%(95%CI:2.30%~2.32%),流感病毒检出阳性率分别为24.27%(95%CI:24.02%~24.51%)和7.15%(95%CI:6.78%~7.54%),流感发病率分别为3.66‰(95%CI:3.62‰~3.70‰)和1.65‰(95%CI:1.57‰~1.74‰)。上海市2020年的ILI%升高了45.25%,流感病毒检出阳性率和流感发病率分别降低了78.45%和51.80%。结论 2020年上海市流感监测网络的运行情况发生改变,ILI%有所升高,流感病毒检出阳性率和流感发病率均有所降低,流感监测质量的改变是一个潜在的影响因素,未来仍需进一步加强流感监测的质量控制。     

中国1～12岁健康儿童接种1剂水痘减毒活疫苗保护效果的系统评价与证据质量分析

目的 系统评价1～12岁健康儿童接种1剂水痘减毒活疫苗保护效果（VE）,探索运用GRADE（Grades of Recommendation, Assessment, Development, and Evaluation）证据质量评级方法评价疫苗效果观察性研究。方法 检索2019年以前关于中国1～12岁健康儿童1剂水痘减毒活疫苗VE的文献,采用纽卡斯尔-渥太华量表进行文献质量评价,采用Meta分析计算水痘疫苗VE,对研究类型、是否为暴发疫情、文献质量、年龄分亚组计算VE。采用GRADE方法评价整合证据质量。结果 共纳入32篇文献,合并后VE值为75%（95% CI：68%～80%）,亚组分析暴发疫情VE（66%,95% CI：57%～73%）低于非暴发疫情［85%（95% CI：78%～89%）］,<6岁儿童VE［84%（95% CI：77%～89%）］高于≥6岁儿童VE［60%（95% CI：51%～68%）］,不同研究类型、不同文献质量的VE差异无统计学意义。整合证据评级VE证据质量为“极低”,分别在偏倚风险和不一致性方面降一级,在间接性、不精确性和发表偏倚方面未降级。结论 中国1～12岁健康儿童1剂次水痘减毒活疫苗可提供中等水平保护,但≥6岁儿童VE明显降低,建议对<6岁儿童开展2剂次水痘疫苗接种。GRADE的证据质量评级方法可用于疫苗效果的观察性研究,建议制定观察性研究技术指南,提高证据体的整体质量。     

深圳市学龄儿童接种流感疫苗对缺课预防效果的实证研究

目的 评估深圳市采用入校接种方式以及学龄儿童流感疫苗接种率高低对缺课的影响。方法 以深圳市小学学龄儿童为研究对象,利用2017年12月至2020年6月深圳市286所小学缺课数据以及学龄儿童流感疫苗接种政策实施后深圳市9个区疫苗接种率和组织方式（入校接种与非入校接种）数据,以缺课人数作为被解释变量,分别以组织方式和区接种率作为分组变量,构建双重差分模型,采用泊松回归进行分析,并对回归结果进行稳健性检验。结果 相比于非入校接种和低接种率,入校接种和高接种率可有效降低缺课的发生风险,对缺课的预防效果分别为32.6%（95%CI： 17.0%~45.3%,P<0.01）和53.0%（95%CI：42.1%~61.8%,P<0.01）。结论 深圳市实施学龄儿童流感疫苗免费接种政策并优先采用入校接种的方式,可有效降低学生缺课的发生风险。     

肠道病毒71型疫苗上市后疫苗保护效果和免疫原性分析

目的 分析肠道病毒71型（EV-A71）疫苗上市接种后的疫苗保护效果和免疫原性。方法 采用队列研究于2017年10－12月在上海市静安区招募符合纳入标准的预防接种门诊受种者为研究对象,按0、30 d程序接种疫苗者纳入接种组,不接种疫苗者纳入对照组,随访观察1年,评估疫苗保护效果和接种2剂次疫苗后抗体水平及阳转率。结果 共纳入3 018名8~20月龄的儿童,接种组1 211人,对照组1 807人,经过1年随访,EV-A71疫苗对EV-A71感染引起的手足口病保护率为100.00%（95% CI：-66.99%~100.00%）。接种组中124人检测了中和抗体,接种首剂疫苗后60 d抗体几何平均滴度（GMT）为41.76（95% CI：35.60~49.34）,接种后365 d GMT为28.44（95% CI：23.59~34.54）。结论 EV-A71疫苗对于儿童有良好的免疫应答,EV-A71感染引起的手足口病病例较少,需进一步观察。     

青海省西宁市医院临床医护人员2016－2017年度流感疫苗接种情况及影响因素分析

目的 了解青海省西宁市临床医护人员2016-2017年度流感疫苗的接种情况及影响因素,初步探索推动西宁市临床医护人员流感疫苗接种措施。方法 随机抽取西宁市4家三级医院,在知情同意的原则下自愿参与完成自填式问卷调查,并访谈医院相关负责人。结果 西宁市三级医院临床医护人员2016-2017年度流感疫苗接种率为5.14%（95%CI：4.80%~5.49%）,多因素分析显示,流感疫苗优先推荐接种人群、接种频次,接种效果的知晓以及职称是主要影响因素。接种组向他人推荐流感疫苗的意愿高于未接种组（χ²=99.57,P<0.001）。结论 西宁市医院临床医护人员流感疫苗接种率低,主要与流感疫苗的认知不足有关。应开展宣传教育,充分发挥示范和影响作用。     

广东省2017－2018年冬季流感流行特征研究

目的 分析广东省2017-2018年冬季流感流行特征,为流感季节性多样化的防控应对提供进一步的科学依据。方法 收集广东省2016年1月至2018年4月每周流感监测数据,分析2017-2018年冬季28家哨点医院门诊流感样病例（ILI）就诊比例、流感病毒阳性率、病原型别构成和暴发疫情特点,并使用χ²检验和Fisher确切概率法与2016年春季、2017年夏季流行期比较。结果 2017-2018年冬季ILI就诊比例平均水平为4.99%（157 235/3 149 656）,超过既往5年同期水平。门诊ILI和住院严重急性呼吸道感染病例（SARI）中,流感病毒阳性率分别为28.33%（2 137/7 543）和14.93%（256/1 715）,乙型Yamagata亚型分别占70.43%（1 505/2 137）和73.05%（187/256）。2017-2018年冬季流感暴发疫情257起,小学占82.49%（212/257）。冬、春季流感6~14岁儿童病例阳性率高于夏季（P<0.05）。夏季≥ 60岁老年人病例阳性率高于冬、春两季（P<0.05）。结论 广东省2017-2018年冬季流感流行主要由流感病毒乙型Yamagata亚型导致。针对流行季节多样性特点,广东省需要完善监测和提高流感疫苗接种率,以利于在不同季节流行有效防控。     

苏州地区2011-2017年5岁以下儿童流感相关严重急性呼吸道感染临床症状和影响因素研究

目的 探讨江苏省苏州地区<5岁儿童流感相关严重急性呼吸道感染（SARI）的影响因素,为完善儿童流感防控策略提供证据支持。方法 基于2011年4月至2017年3月在苏州大学附属儿童医院持续开展的前瞻性流感监测的相关数据,χ²检验比较流感相关流感样疾病（ILI）和流感相关SARI之间的临床特征,非条件logistic回归分析流感相关SARI的影响因素。结果 共收集流感相关ILI 786例,流感相关SARI 413例。咳嗽、流涕、气促、哮喘/喘息等临床症状在流感相关SARI中出现的比例显著高于流感相关ILI（P<0.01）。单因素和多因素logistic回归分析结果显示,年龄<6月龄（OR=3.6）、6~23月龄（aOR=2.5）、3个月内呼吸道感染史（aOR=4.5）、慢性肺部疾病史（OR=3.4）、发热热峰39.0~39.9℃（aOR=2.4）、≥40℃（aOR=6.0）、甲型（H1N1）（aOR=2.3）和甲型（H3N2）（aOR=1.9）流感病毒感染是流感相关SARI的影响因素。结论 年龄<2岁、有慢性肺部疾病史、有3个月内呼吸系统感染史以及发热热峰≥39.0℃的儿童应尽早就医,或每年接种流感疫苗,以减少流感相关严重结局的发生。     

中国2013年成年人二手烟暴露水平及相关危害认知情况调查

目的 了解2013年我国成年人二手烟暴露水平及对二手烟暴露导致相关疾病的认知情况。方法 利用中国2013年慢性病及其危险因素监测样本人群,在302个监测点采用多阶段分层整群抽样方法,通过面对面询问的方式收集相关信息,共计调查179 570人,其中纳入有效样本量为176 179人。对样本进行复杂加权后,分析我国成年人二手烟暴露情况,以及对二手烟暴露导致相关疾病的知晓率。结果 调查人群经过复杂加权计算后,18岁以上人群二手烟暴露率为52.8%（95%CI：51.2%~54.4%）,且随年龄增大有下降趋势（χ²=515.8,P<0.000 1）,以商业服务职业人群最高（61.6%,95%CI：58.6%~64.5%）。二手烟暴露导致疾病知晓率为67.9%（95%CI：65.8%~69.9%）。城镇（77.0%,95%CI：75.0%~79.1%）高于乡村（60.0%,95%CI：57.7%~62.4%）,男性（69.8%,95%CI：67.8%~71.7%）高于女性（65.9%,95%CI：63.7%~68.1%）。对3种疾病的知晓率,城镇居民（49.8%,95%CI：47.3%~52.4%）高于乡村居民（37.9%,95%CI：35.4%~40.5%）;知晓二手烟暴露导致成年人肺部疾病的比率最高（88.5%,95%CI：87.5%~89.5%）,其次为儿童肺部疾病（70.0%,95%CI：68.1%~71.9%）,对二手烟暴露导致成年人心脏疾病的知晓率为最低（46.8%,95%CI：44.6%~49.1%）。结论 中国18岁以上成年人二手烟暴露水平较高,对二手烟暴露导致疾病尤其是成年人心脏疾病的知晓率较低。     

苏州市2011-2017年5岁以下儿童流感门诊病例临床特征及疾病负担

目的 了解2011-2017年苏州大学附属儿童医院<5岁儿童流感样病例（ILI）临床特征及疾病负担。方法 2011年3月至2017年2月于苏州市儿童医院监测因流感样疾病就诊的<5岁门诊病例,通过问卷调查和电话随访收集人口学信息、临床信息、疾病史及与医疗有关的直接和间接费用,比较ILI及不同流感亚型确诊病例的临床特征和社会经济负担。结果 共纳入6 310例,其中791例（12.9%）流感病毒检测阳性,其中A/H1N1阳性88例（11.1%）,A/H3N2阳性288例（36.4%）,B型415例（52.5%）。流感阳性儿童发生咳嗽、流涕、喘息、呕吐、抽搐的比例皆高;A/H1N1、A/H3N2、B型感染导致临床特征的主要差异为咳嗽（χ²=9.227,P=0.010）、喘息（χ²=7.273,P=0.026）和呕吐（χ²=8.163,P=0.017）。流感病毒阴性者治疗平均费用688.4（95%CI：630.1~746.7）元,流感病毒阳性者为768.0（95%CI：686.8~849.3）元。A/H1N1阳性者治疗总费用明显高于A/H3N2阳性和B型阳性者（χ²=7.237,P=0.028）。结论 儿童感染流感病毒更易发生咳嗽、流涕、喘息、呕吐、抽搐等临床症状,并造成严重的疾病负担,其中A/H1N1亚型感染造成的疾病负担高于其他2种亚型。     

江西省2013年成年人吸烟与戒烟行为现状调查

目的 调查2013年江西省≥18岁常住居民吸烟与戒烟行为的流行状况。方法 2013年7-10月采用多阶段分层整群随机抽样方法,在江西省10个全国慢性病及其危险因素监测点抽取≥18岁常住居民6 000人,通过面对面问卷调查收集慢性病相关危险因素信息,用于吸烟与戒烟行为分析的有效样本量为5 997人。对样本进行复杂加权后,分析江西省不同人群特征成年居民吸烟和戒烟流行现状。结果 2013年江西省≥18岁常住居民现在吸烟率为21.53%（1 291/5 997,标化率为20.60%）,复杂加权计算后,现在吸烟率为26.07%（95%CI：23.48%~28.66%）,男性现在吸烟率（50.62%,95%CI：46.31%~54.94%）高于女性（1.46%,95%CI：0.57%~2.35%）,差异有统计学意义（P<0.05）,各年龄组人群现在吸烟率差异有统计学意义（P=0.029）,并随文化程度提高而上升（P<0.05）、随自报健康状况下降而下降（P<0.05）。87.16%（95%CI：83.29%~91.03%）的现在吸烟者每日吸烟;日均吸烟量（机制卷烟）为19.27（95%CI：17.69~20.85）支;平均每天吸烟量≥20支的吸烟者比例为64.74%（95%CI：55.79%~73.70%）;每日吸烟者开始吸烟平均年龄为20.28（95%CI：19.74~20.82）岁,男性开始每日吸烟年龄[20.11（95%CI：19.61~20.61）岁]小于女性[26.88（95%CI：24.73~29.03）岁],差异有统计学意义（P<0.05）,27.04%（95%CI：18.91%~35.16%）的成年男性开始每日吸烟年龄不足18岁。吸烟者戒烟率为14.80%（95%CI：10.88%~18.72%）,随年龄增大而上升（P<0.05）、随收入水平增加而上升（P=0.04）,随自报健康状况下降而上升（P<0.05）;吸烟者成功戒烟率为10.89%（95%CI：8.36%~13.42%）;32.10%（95%CI：21.95%~42.25%）的现在吸烟者有戒烟打算。被动吸烟率为54.71%（95%CI：44.20%~65.21%）。结论 江西省≥18岁常住居民吸烟率处于较高水平,重度吸烟者比例大,戒烟者比例低,戒烟意识不强,男性和青少年为控烟工作主要目标人群,应根据江西省流行特点采取针对性的控烟措施。     

流感减毒活疫苗预防儿童季节性流感保护效果的Meta分析

目的评价流感减毒活疫苗(LAIV)预防2~17岁儿童季节性流感的保护效果。方法通过Web of Science、PubMed和ScienceDirect数据库,检索2003年1月至2018年11月期间发表的、研究设计为病例对照的、关于研究LAIV预防儿童季节性流感保护效果的相关文献,采用Stata 13.1软件对纳入文献进行Meta分析。结果共纳入文献14篇,均为检测阴性设计(Test-negative design,TND)研究。结果显示LAIV预防儿童季节性流感的保护效果为49%(95%CI:40%~57%)。亚组分析发现:LAIV预防A(H1N1)pdm09型、A(H3N2)型和B型流感的保护效果分别为35%(95%CI:5%~56%)、35%(95%CI:21%~46%)和71%(95%CI:55%~82%);三价LAIV和四价LAIV在儿童中的保护效果分别为56%(95%CI:48%~63%)和44%(95%CI:27%~57%);LAIV在欧洲地区和北美洲地区的保护效果分别为65%(95%CI:47%~77%)和46%(95%CI:36%~55%)。结论LAIV对2~17岁儿童季节性流感具有一定的预防作用。     

Influenza vaccine effectiveness against laboratory-confirmed influenza in a vaccine-mismatched influenza B-dominant season

BackgroundThe 2017–2018 influenza season in Israel was characterized by the predominance of influenza B Yamagata, with a lesser circulation of influenza A(H1N1)pdm09 and influenza A(H3N2). We estimated vaccine effectiveness (VE) of the inactivated influenza vaccine which was selected for use that season.MethodsEnd-of-season VE and 95% confidence intervals (CI) against laboratory-confirmed influenza-like illness (ILI) were estimated by means of the test-negative design. Age-specific VE analysis was carried out using a moving age interval.ResultsSpecimen were obtained from 1,453 community ILI patients; 610 (42.0%) were influenza-positive, among which 69.7% were B, 17.2% A(H1N1)pdm09 and 13.4% A(H3N2). A 98.6% of molecularly characterized influenza B belonged to the Yamagata lineage. Of the sampled individuals, 1320 were suitable for VE analysis. Of those vaccinated, 90.6% received the inactivated trivalent influenza vaccine (TIV) containing a Victoria lineage influenza B-like virus. VE against influenza A differed by age, with the highest VE of 72.9% (95%CI 31.9–89.2%) observed in children 0.5–14 years old, while all ages VE was 46.6% (95%CI 10.4–68.2%). All ages VE against influenza B was 23.2% (95%CI −10.1–46.4%) with age-specific analysis showing non-significant VE estimates. Utilizing a moving age interval of 15 years, afforded a detailed age-specific insight into influenza VE against the influenza viruses circulating during the 2017–2018 season.ConclusionsThe moderate-high 2017–2018 influenza A VE among children and adolescents, supports seasonal influenza vaccination at a young age. The low VE against influenza B in Israel, is most likely the result of influenza B/TIV-mismatch.     

应用调整Serfling回归模型估计北京市5岁以下儿童病毒性腹泻相关超额病例数

目的 构建调整Serfling回归模型,估计北京市2011年至2015年5月23日病毒性腹泻相关 <5岁儿童超额腹泻病例数。方法 利用北京市2家儿童专科医院 <5岁儿童急性腹泻周就诊病例数,拟合调整Serfling回归模型,估计其病毒性腹泻相关超额病例数。结果 北京市2011年第8～10周、40～42周,2012年第40～46周,2013年第43～49周,2014年第45周直到2015年第11周为病毒性腹泻流行周。2家儿童专科医院各年度流行周 <5岁儿童病毒性腹泻相关超额就诊病例数分别为911(95%CI:261～1 561)、1 998(95%CI:1 250～2 746)、1 645(95%CI:891～2 397)、2 806(95%CI:1 938～3 674)、1 822(95%CI:614～3 031)例,分别占同期全部 <5岁儿童腹泻就诊病例数的40.38%(95%CI:11.57%～69.19%)、44.21%(95%CI:27.66%～60.77%)、45.08%(95%CI:24.42%～65.69%)、60.87%(95%CI:42.04%～79.70%)和66.62%(95%CI:22.45%～110.82%)。估计北京市2011年至2015年5月23日 <5岁儿童病毒性腹泻相关超额就诊病例数为18 731(95%CI:10 106～27 354)例。结论 冬季是 <5岁儿童病毒性腹泻发病及就诊高峰。调整Serfling回归模型提示:应关注致急性胃肠炎病毒,尤其是诺如病毒的病原学变化。     

Effectiveness of quadrivalent influenza vaccination in the first year of a funded childhood program in Queensland,Australia, 2018

BackgroundFollowing high influenza activity in 2017, the state of Queensland, Australia, funded a quadrivalent inactivated influenza vaccination program for children aged 6 months to <5 years in 2018. We calculated influenza vaccine effectiveness (VE) among children eligible for this program.MethodsA matched case-control study was conducted. Cases were identified using Queensland 2018 influenza notification data among children age-eligible for funded vaccination. Controls were drawn from Australian Immunisation Register records of Queensland resident children age-eligible for funded influenza vaccine. Up to 10 controls per case were matched for location and birthdate. First dose vaccination was valid if received ≥14 days prior to specimen collection; a second dose was valid if received ≥28 days after first dose receipt. VE was calculated for vaccine doses and adherence to national recommendations for two doses in the first season (schedule completeness) and adjusted (VE_adj) for sex and First Nations status.ResultsThere were 1,125 cases and 10,645 matched controls analysed. Overall VE_adj against laboratory-confirmed influenza was 51% (95% confidence interval (CI) 41–60). VE_adj was 60% (95% CI 46–70) for children who received two doses in 2018, and 60% (95% CI 48–69) for children vaccinated appropriately according to schedule completeness. VE increased with age.ConclusionsModerate vaccine effectiveness was observed for children eligible for the funded program in Queensland in 2018, adding to the sparse evidence for influenza vaccine use in Australian children. Adhering to the national first season two dose schedule for influenza vaccine receipt in children ensures maximum protection.     

Seasonal influenza vaccine effectiveness against medically attended influenza illness among children aged 6–59 months,October 2011–September 2012: A matched test-negative case–control study in Suzhou,China

BackgroundSeasonal influenza infections among young children in China lead to substantial numbers of hospitalizations and financial burden. This study assessed the seasonal influenza vaccine effectiveness (VE) against laboratory confirmed medically attended influenza illness among children in Suzhou, China, from October 2011–September 2012.MethodsWe conducted a test-negative case–control study among children aged 6–59 months who sought care at Soochow University Affiliated Children's Hospital (SCH) from October 2011–September 2012. A case was defined as a child with influenza-like illness (ILI) or severe acute respiratory infection (SARI) with an influenza-positive nasopharyngeal swab by rRT-PCR. Controls were selected from children presenting with ILI or SARI without laboratory confirmed influenza. We conducted 1:1 matching by age and admission date. Vaccination status was verified from the citywide immunization system database. VE was calculated with conditional logistic regression: (1 − OR) × 100%.ResultDuring the study period, 2634 children aged 6–59 months presented to SCH with ILI (1975) or SARI (659) and were tested for influenza. The vaccination records were available for 69% (1829; ILI: 1354, SARI: 475). Among those, 23% (427) tested positive for influenza, and were included as cases. Among influenza positive cases, the vaccination rates were 3.2% for SARI and 4.5% for ILI. Among controls, the vaccination rates were 13% for SARI, and 11% for ILI. The overall VE against lab-confirmed medically attended influenza virus infection was 67% (95% CI: 41–82). The VE for SARI was 75% (95% CI: 11–93) and for ILI was 64% (95% CI: 31–82).ConclusionsThe seasonal influenza vaccine was effective against medically attended lab-confirmed influenza infection in children aged 6–59 months in Suzhou, China in the 2011–12 influenza season. Increasing seasonal influenza vaccination among young children in Suzhou may decrease medically attended influenza-associated ILI and SARI cases in this population.     

Negative impact of prior influenza vaccination on current influenza vaccination among people infected and not infected in prior season: A test-negative case-control study in Japan

BackgroundAccumulating evidences indicate that repeated influenza vaccination has negative impact on the vaccine effectiveness (VE). However no published studies considered past influenza infection when assessing the VE of repeated vaccination.MethodsProspective surveillance was conducted from 2009 to 2012 at a community hospital on a small island in Japan. The study included all outpatients with an influenza-like illness (ILI) who attended the hospital, and a rapid diagnostic test (RDT) was used to diagnose influenza A/B infection. The VE of trivalent inactivated influenza vaccine (TIV) against medically attended influenza A (MA-fluA) was estimated using a test-negative case-control study design. The influence of TIV in the prior season on VE in the current season was investigated in the context of MA-fluA during the prior season.ResultsDuring the three influenza seasons, 5838 ILI episodes (4127 subjects) were analysed. Subjects who had an episode of MA-fluA in the prior season were at a significantly lower risk of MA-fluA in the current season (adjusted odds ratio: 0.38, 95% CI: 0.30–0.50). The overall adjusted VE was 28% (95% CI, 14–40). VE was substantially lower in subjects vaccinated in the prior season compared to those who had not been vaccinated in prior season (19%; 95% CI: 0–35 vs 46%; 95% CI: 26–60, test for interaction, P value <0.05). In subjects who did not have MA-fluA in the prior season showed the attenuation of VE due to repeated vaccination (13%; 95% CI: −7 to 30 vs 44%; 95% CI: 24–59, test for interaction, P < 0.05). However this effect was not detected in subjects who had contracted MA-fluA in the prior season.ConclusionsNegative effects of repeated vaccination were significant among those without history of MA-fluA in the prior season.     

Lineage-matched versus mismatched influenza B vaccine effectiveness following seasons of marginal influenza B circulation

BackgroundSeveral countries have recently transitioned from the trivalent inactivated influenza vaccine (TIV) to the quadrivalent inactivated influenza vaccine (QIV) in order to outweigh influenza B vaccine-mismatch. However, few studies thus far evaluated its benefits versus the TIV in a systematic manner. Our objective was to compare the QIV VE with lineage-mismatched TIV VE.MethodsWe estimated the 2015–2016, 2017–2018, 2019–2020 end-of season influenza B VE against laboratory-confirmed influenza-like illness (ILI) among community patients, using the test-negative design. VE was estimated for pre-determined age groups and for moving age intervals of 15 years.ResultsSince 2011–2012 season, alternate seasons in Israel were dominated by influenza B circulation. Compared with the lineage-mismatched TIV used during the 2015–2016 and 2017–2018 seasons, the 2019–2020 QIV showed the highest all-ages VE, with VE estimates of 56.9 (95% CI 30.1 to 73.4), 16.5 (95% CI –22.5 to 43.1) and ?25.8 (95% CI ?85.3 to 14.6) for the 2019–2020, 2017–2018 and 2015–2016 seasons, respectively. The 2019–2020 VE point estimated were the highest for the 0.5–4, 5–17 and 18–44 years age groups and for more 15-year age intervals as compared to the other seasons.ConclusionsOur results support the rapid transition from the TIV to the QIV.     

Inactivated influenza vaccine effectiveness and an analysis of repeated vaccination for children during the 2016/17 season

ObjectivesWe assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children 6 months to 15 years of age during the 2016/17 season. In addition, we estimated the impact of repeated vaccination in children on VE.MethodsOur study for VEs in preventing influenza and admission due to influenza were conducted according to a test-negative case-control design (TNCC) based on influenza rapid diagnostic test results. We also analyzed the VE by vaccine status in the current and previous seasons for the impact of repeated vaccination.ResultsDuring the 2016/17 season, the quadrivalent IIV was used in Japan. The adjusted VE in preventing influenza illness was 38% (95% CI, 29–46) against influenza A and 39% (95% CI, 18–54) against influenza B. Infants showed no significant VE. The VE in preventing hospitalization was not demonstrated. For the analysis of repeated vaccination, the vaccine was effective only when immunization occurred in the current season. The children who were immunized in two consecutive seasons were more likely to develop influenza compared to those immunized in the current season only (odds ratio, 1.58 [95% CI, 1.05–2.38], adjusted odds ratio, 1.53 [95% CI, 0.99–2.35]). However, the odds ratio of repeated vaccination was not significant when the analysis excluded those who developed influenza in the previous season.ConclusionsVE in children in the 2016/17 season was similar to values previously reported. Repeated vaccination interfered with the VE against any influenza infection in the 2016/17 season. The results of our study suggest that decreased VE by repeat vaccination phenomenon was associated with immunity by influenza infection in the previous season. However, the influenza vaccine should be recommended every season for children.     

Effectiveness of seasonal influenza vaccine in adult Japanese workers, 2017–2020

BackgroundPrevious studies have not estimated vaccine effectiveness (VE) against influenza in the working-age Japanese population. In this study, we determined VE in adult workers at a Japanese company.MethodsWe estimated VE based on self-reported data regarding influenza infections and vaccinations in employees of an auto parts manufacturing company during three influenza seasons from 2017 to 2020. VE was estimated as 100% × [1 ? odds ratio (the ratio of the odds of being diagnosed with influenza among enrollees with and without influenza vaccination)]. Odds ratios were estimated using logistic regression.ResultsWe included 11,347 worker records [3,592 (2017–18), 3,663 (2018–19), and 4,092 (2019–20)] from employees who had worked with the company throughout each influenza season. The adjusted VE was moderate and significant in the 2019–20 season (VE = 53%; 95% confidence interval [CI] = 30% to 69%) but low or negative and non-significant during the 2017–18 (VE = 28%; 95% CI = -5% to 50%) and 2018–19 (VE = -11%; 95% CI =  - 42% to 14%) seasons.ConclusionsInfluenza vaccines were moderately effective during the 2019–20 season but showed low or negative effectiveness during the 2017–18 and 2018–19 seasons. Self-reports from worker records can successfully help determine VE against influenza.