干休所75岁以上老年人接种流感疫苗效果观察

目的 评价居住在干休所中75岁以上老年人流感疫苗接种的预防效果.方法 2007年9～11 月选取干休所接种流感疫苗的 162 例 75 岁以上老年人为接种组;同时按照年龄、性别、合并慢性疾病情况匹配,选取未接种流感疫苗的 157例 75 岁以上老年人为对照组.调查分析流感疫苗接种后 1 年内两组老年人流感样疾病发病及就...     

干休所75岁以上老年人接种流感疫苗效果观察

目的评价居住在干休所中75岁以上老年人流感疫苗接种的预防效果。方法 2007年9～11月选取干休所接种流感疫苗的162例75岁以上老年人为接种组;同时按照年龄、性别、合并慢性疾病情况匹配,选取未接种流感疫苗的157例75岁以上老年人为对照组。调查分析流感疫苗接种后1年内两组老年人流感样疾病发病及就诊情况,以及慢性心脑血管疾病、慢性呼吸系统疾病、糖尿病等发病(复发)及就诊情况。结果接种组流感样疾病患病率22.22%,就诊率19.75%,均明显低于对照组患病率33.12%,就诊率31.21%,(P<0.05)。接种组心脑血管疾病、呼吸系统疾病、糖尿病(复发)患病率与对照组比较差异无统计学意义,就诊率62.96%明显低于对照组78.98%(P<0.01)。接种组接种疫苗后26例(16.05%)出现局部或全身反应,经对症处理后均恢复正常。结论接种流感疫苗可有效减少75岁以上老年人流感样疾病的发生,并能减少心脑血管疾病、呼吸系统疾病、糖尿病等疾病的就诊率。     

椒江区老年人接种流感疫苗的保护效果

目的评价台州市椒江区≥60岁老年人接种流感疫苗的保护效果,为推进老年人流感疫苗免费接种项目和提高流感疫苗接种率提供依据。方法在椒江区随机选取500名于2017年9—10月免费接种流感疫苗的≥60岁老年人为接种组,在相同社区选择性别、年龄和健康状况等因素1∶1匹配的从未接种过流感疫苗500名老年人为对照组,在疫苗接种(或基线调查)后12个月内随访调查流感样疾病(ILI)及并发症发生情况等,并评价流感疫苗的保护效果。结果496名接种组和479名对照组完成了全程随访调查。接种组老年人12个月内ILI发病率为8.06%,低于对照组的19.42%(P0.05),流感疫苗对ILI的保护率为58.46%。疫苗接种后3个月,接种组老年人因呼吸系统疾病门诊就诊率和住院率分别为5.44%和4.44%,均低于对照组的20.67%和8.35%(P0.05);两组接种后6个月和12个月的门诊就诊率和住院率差异均无统计学意义(P0.05)。结论老年人接种流感疫苗能有效预防ILI,降低因呼吸系统疾病的门诊就诊率和住院率。     

社区老年人接种流感疫苗的效果评价

目的:对社区老年人接种流感疫苗后的效果进行评价.方法:将2015年10月-12月来中心接种流感疫苗≥60岁的100名老年人作为观察组,同时选取社区到中心就诊的性别、年龄、健康状况等与观察组各方面条件相似的未进行流感疫苗接种的100名老年人为对照组.在观察组老年人接种流感疫苗3个月后,对这两个组的老年人分别进行问卷调查,对他们流感样疾病的发生及就诊情况进行对比、统计分析.结果:对照组老年人流感样疾病的发生率、就诊率明显高于观察组老年人,两组老年人具有明显差异,具有统计学意义(P<0.05).结论:老年人接种流感疫苗后可以明显减少流感样疾病的发生率、就诊率,对预防流感样疾病起到很好的效果.     

东丽区65岁以上老人流感疫苗接种效果评估

目的评价东丽区65岁以上户籍老年人免费接种流感疫苗的效果。方法选取东丽区2 0 1 4年免费接种过流感疫苗的51 2人65岁以上老年人为接种组,同时选取与接种组性别、年龄、身体状况等相匹配未接种过流感疫苗的3 60名65岁以上老年人为对照组,在流感疫苗接种后半年开展问卷调查,分析两组流感样症状及并发症的发病情况。结果接种流感疫苗对流感样症状的保护率为83.4 7%;对感冒后合并心肺并发症的保护率为81.73%;对普通感冒样症状的保护率为2 8.4 6%;接种流感疫苗发生接种反应的发生率为4.4 9%,均为一般反应。结论老年人接种流感疫苗安全有效。     

2008年胶南市部分农村合作医疗人群接种季节性流感疫苗成本效益分析

[目的]评价胶南市参加农村合作医疗人群接种季节性流感疫苗(以下简称流感疫苗)的效果和效益。[方法]2008年10月按年龄段分组选取3个社区共375名流感疫苗接种者为接种组,随机选择年龄、性别、健康状况、经济收入及受教育程度等相匹配的未接种流感疫苗的人群作为对照组,采用流行病学试验研究方法,随访12个月进行调查分析。[结果]疫苗对流感样疾病(ILI)的平均保护率为56.62%,其中60岁以上年龄组为69.23%。[结论]疫苗具有良好的保护性,特别是老年人群效果明显。且流感疫苗接种于60岁以上老年人可产生较高的经济效益,人均每年流感样疾病医疗费用节约约92元,建议农村合作医疗若按照40%的比例报销农村老年人流感疫苗接种费用,将会收到较好的经济效益和社会效益。     

243名军队离退休人员流感疫苗预防接种效果观察

目的调查军队离退休人员接种流感疫苗预防流感的效果。方法选取驻京某军队医院2005年10~12月接种过流感疫苗的243名军队离退休人员为接种组,同时按照年龄、性别、疾病匹配的情况选取未接种流感疫苗的220名地方人员为对照组。调查分析流感疫苗接种后1年内两组流感样疾病,心血管、呼吸、内分泌系统疾病发生情况。结果接种组流感样疾病发生率(22.2%)和就诊率(18.1%)均明显低于对照组〔(33.2%)和(31.8%)〕(P<0.05,P<0.01)。接种组心脑血管、呼吸、内分泌系统疾病发生率与对照组比较差异无统计学意义,就诊率(71.2%)明显低于对照组(93.6%,P<0.01)。接种组1年内流感样疾病保护率为33.1%,减少就诊率43.1%;心脑血管、呼吸、内分泌系统疾病减少就诊率23.9%。结论接种流感疫苗既减少了老年人流感样疾病的发生率,还降低了心脑血管、呼吸、内分泌等系统疾病的就诊率。     

老年人接种流感疫苗的效果评价

目的评价老年人接种流感疫苗的效果。方法选取670名离退休教职工为接种组,675名未接种离退休人员为对照组,在接种流感疫苗后的第3个月采取问卷调查。分析两组流感样疾病的发生及治疗情况。结果接种疫苗后3个月,接种组和对照组流感样疾病的发病率分别为11.2%和23.7%,差异有统计学意义(P0.01)。流感疫苗的保护率为52.7%。对照组和接种组患者服用1种药物的比率分别是66.7%和25.0%,服用2种及多种药物的比率为33.3%和75.0%,差异均有统计学意义(P0.01)。结论接种流感疫苗对老年人具有一定的保护作用。     

老年人接种流感疫苗的效果评价

目的评价老年人接种流感疫苗的效果。方法选取670名离退休教职工为接种组,675名未接种离退休人员为对照组,在接种流感疫苗后的第3个月采取问卷调查。分析两组流感样疾病的发生及治疗情况。结果接种疫苗后3个月,接种组和对照组流感样疾病的发病率分别为11.2%和23.7%,差异有统计学意义(P<0.01)。流感疫苗的保护率为52.7%。对照组和接种组患者服用1种药物的比率分别是66.7%和25.0%,服用2种及多种药物的比率为33.3%和75.0%,差异均有统计学意义(P<0.01)。结论接种流感疫苗对老年人具有一定的保护作用。     

2018-2019年台州市老年人接种流感疫苗的成本效益北大核心

目的评价台州市老年人2018-2019年接种流感疫苗的成本效益。方法采用前瞻性队列研究在社区招募≥60岁老年人分为流感疫苗接种组和非接种组,随访6个月,收集流感样病例经济负担和流感疫苗接种成本相关数据,计算接种流感疫苗的效益成本比。结果共纳入2073名研究对象,其中流感疫苗接种组1048名、非接种组1025名,流感样病例总经济负担中位数为552.9元,其中直接医疗费用200.0元、直接非医疗费用0.0元、间接费用为217.9元。人均流感疫苗接种成本为35.50元,其中疫苗、人力、工作经费成本分别为32.38元、2.63元、0.49元。人均接种流感疫苗效益为199.1元,效益成本比为5.6:1。结论2018-2019年台州市老年人接种流感疫苗具有良好的成本效益。     

Vaccine effectiveness for laboratory-confirmed influenza in children 6-59 months of age, 2005-2007

To estimate the effectiveness of influenza vaccine against medical care visits for laboratory-confirmed influenza in young children we conducted a matched case-control study in children with acute respiratory illness or fever from 2005-2007. Influenza vaccine effectiveness (VE) was calculated using cases with laboratory-confirmed influenza and controls who tested negative for influenza. The effectiveness of influenza vaccine in fully vaccinated children 6-59 months of age was 56% (95% CI: 25%-74%); a significant VE was not found for partial vaccination.     

The Relationship between Influenza Vaccination and Outpatient Visits for Upper Respiratory Infection by the Elderly in Taiwan

OBJECTIVE: To evaluate the effect of influenza vaccination on the reduction of the risk of outpatient visits for upper respiratory infection (URI) among the elderly in Taiwan. METHODS: The data for this observational study, consisting of 1729 people aged 65 years or older, were drawn from Taiwan's 2001 National Health Interview Survey. This survey data was then linked with National Health Insurance claim data for December 2001 to November 2002. Survival analysis of Cox proportional hazards model was performed to examine the risk of URI outpatient visits in elderly people vaccinated with the influenza vaccine and those not vaccinated during a year-long study period since the influenza season began. To adjust for potential self-selection bias, we used propensity score method to categorize individuals into two groups, based on the predicted probability of being vaccinated from a logistic regression of spatial random effect. Propensity score group 1 (PSG 1) were those with a predicted probability of being vaccinated lower than 0.5, and PSG 2 were those with a predicted probability of being vaccinated of 0.5 or higher. RESULTS: The overall vaccination rate was 50%. Logistic regression showed the probability of being vaccinated was related to the number of outpatient visits for URI before the influenza season began (odds ratio (OR) 1.07; 95% confidence interval (CI) 1.04-1.10). Our first survival analysis showed that being vaccinated significantly reduced the risk of URI outpatient visits in PSG 2 during the 1-year study period (hazard ratio 0.89; 95% CI 0.81-0.97). Separate survival analysis showed that being vaccinated reduced the risk of URI outpatient visits for both PSG groups during the first 3 months of the study period. CONCLUSION: Being vaccinated could reduce the risk of outpatient visits for URI among the elderly during the influenza season.     

Effectiveness of repeated influenza vaccination among the elderly population with high annual vaccine uptake rates during the three consecutive A/H3N2 epidemics

BackgroundAnnually, about 80% of the Korean elderly aged ≥65 years receive influenza vaccination. Repeated annual vaccination has been suggested as an important factor of poor influenza vaccine effectiveness (VE), though reported conflicting results.MethodsDuring the consecutive A/H3N2-dominant influenza seasons between 2012 and 2015, we comparatively evaluated the VE (repeated vs. current season only) against laboratory-confirmed influenza, pneumonia and hospitalization in the elderly aged ≥65 years with influenza-like illness (ILI). Clinical and demographic data were collected prospectively, and vaccination status of prior and current seasons was verified using the immunization registry data of Korean Centers for Disease Control and Prevention.ResultsDuring the first A/H3N2-dominant season in 2012–2013, influenza vaccine showed statistically significant effectiveness against influenza A infection only and when vaccinated in the current season only (VE 53%, 95% CI 15–77). In the latter two seasons (2013–2015 years), the adjusted VE for influenza A was indistinguishable between repeated vaccination and vaccination in the current season only.ConclusionDuring consecutive influenza A/H3N2 epidemics, poor influenza vaccine effectiveness may be more pronounced among the elderly population with a high annual vaccine uptake rate.     

Influenza vaccine effectiveness by test-negative design – Comparison of inpatient and outpatient settings

BackgroundObservational studies of influenza vaccine effectiveness (VE) are increasingly using the test-negative design. Studies are typically based in outpatient or inpatient settings, but these two approaches are rarely compared directly. The aim of our study was to assess whether influenza VE estimates differ between inpatient and outpatient settings.MethodsWe searched the literature from Medline, PubMed and Web of Science using a combination of keywords to identify published studies of influenza VE using the test-negative design. Studies assessing any type of influenza vaccine among any population in any setting were considered, while interim studies or re-analyses were excluded. Retrieved articles were reviewed, screened and categorized based on study setting, location and influenza season. We searched for parallel studies in inpatient and outpatient settings that were done in the same influenza season, in the same location, and in the same or similar age groups. For each of the pairs identified, we estimated the difference in VE estimates between settings, and we tested whether the average difference was significant using a paired t-test.ResultsIn total 25 pairs of estimates were identified that permitted comparisons between VE estimates in inpatient and outpatient study settings. Within pairs, the prevalence of influenza was generally higher among patients enrolled in the outpatient studies, while influenza vaccination coverage among the test-negative control groups was generally higher in the inpatient studies. There was no heterogeneity in the paired differences in VE, and the pooled difference in VE between inpatient and outpatient studies was −2% (95% confidence interval: −12%, 10%).ConclusionsWe found no differences in VE estimates between inpatient and outpatient settings by studies using the test-negative design. Further research involving direct comparisons of VE estimates from the two settings in the same populations and years would be valuable.     

2013-2014年度季节性流行性感冒疫苗对儿童保护效果的病例对照研究

目的 评价2013-2014年度季节性流行性感冒疫苗（流感疫苗）对6~59月龄儿童的保护效果。方法 选择2013-2014年度6~59月龄的实验室诊断流感病例为病例组,在广州市免疫规划系统中随机选择健康儿童为对照组,进行成组病例对照研究,采用非条件Logistic回归计算保护效果。结果 本研究共纳入2 690名研究对象。2013-2014年度,流感疫苗对6~59月龄儿童的保护效果为42.3%（95% CI:27.8%~53.8%）,对36~59月龄儿童的保护效果高于6~35月龄儿童,完全免疫的保护效果高于部分免疫,性别间保护效果无统计学差异。结论 流感疫苗对6~59月龄儿童具有中等保护效果,建议6~59月龄儿童每年接种流感疫苗。     

Effectiveness of pandemic and seasonal influenza vaccines in preventing pandemic influenza-associated hospitalization

Vaccines are leading pharmacological measures for limiting the impact of pandemic influenza in the community. The objective of this study was to investigate the effectiveness of influenza (pandemic and seasonal) vaccines in preventing pandemic influenza-associated hospitalization. We conducted a multicenter matched case-control study in 36 Spanish hospitals. Patients hospitalized with confirmed pandemic influenza between November 2009 and February 2010 and two hospitalized controls per case, matched according to age, date of hospitalization and province of residence, were selected. Multivariate analysis was performed using conditional logistic regression. Subjects were considered vaccinated if they had received the vaccine >14 days (seasonal influenza vaccine) or >7 days (pandemic influenza vaccine) before the onset of symptoms (cases) or the onset of symptoms of the matched case (controls). For the pandemic influenza vaccine, vaccination effectiveness (VE) was estimated taking into account only patients recruited from November 23, 2009, seven days after the beginning of the pandemic influenza vaccination campaign. 638 cases and 1250 controls were included. The adjusted VE of the pandemic vaccine in the ≥18 years age group was 74.2% (95% CI, 29-90) and that of the influenza seasonal vaccine 15.0% (-34 to 43). The recommendation of influenza vaccination should be reinforced as a regular measure to reduce influenza-associated hospitalization during pandemics and seasonal epidemics.     

Influenza vaccine effectiveness in preventing hospitalization among Beijing residents in China, 2013–15

BackgroundEstimates of influenza vaccination effectiveness (VE) are valuable for populations where the vaccine has been promoted in order to support vaccination policy and to permit evaluation of vaccination strategies. Such studies would be important for China due to limited data available during seasons when the vaccine strains matched or mismatched the circulating viruses.MethodsWe conducted a test-negative study in hospitals in Beijing. Patients admitted to five hospitals in the city were enrolled during the winter influenza seasons of 2013–14 and 2014–15. Influenza virus infections were determined by PCR, and influenza vaccination records were extracted from a centralized electronic immunization registry. Influenza VE was estimated by logistic regression adjusting for age group, sex and chronic conditions, and matched by calendar week.ResultsA total of 2368 inpatients were recruited during the study period with a vaccination coverage in the control group of 12.8%. The overall estimate of influenza VE was 46.9% (95% CI: −20.4%, 76.6%) for the 2013–14 season and 5.0% (95% CI: −53.0%, 41.0%) for the 2014–15 season. Estimates of VE were relatively higher in children aged 6–17 years than older persons across two influenza seasons while estimates of VE for both adults and elderly were relatively low.ConclusionsOur findings were consistent with expected influenza vaccination effectiveness in seasons when the vaccine matched or mismatched circulating viruses. Strategies to increase influenza vaccine coverage could provide a public health benefit.     

A real-world study evaluating the relative vaccine effectiveness of a cell-based quadrivalent influenza vaccine compared to egg-based quadrivalent influenza vaccine in the US during the 2017–18 influenza season

BackgroundCell-based influenza vaccine manufacturing reduces egg adaptations that can decrease vaccine effectiveness. We evaluated the relative vaccine effectiveness (rVE) of cell-based quadrivalent influenza vaccine (QIVc) compared to standard-dose egg-based quadrivalent influenza vaccines (QIVe-SD) against influenza-related and serious respiratory events among subjects 4–64 years of age during the 2017–18 influenza season.MethodsA retrospective cohort analysis was conducted using administrative claims data in the US (IQVIA PharMetrics Plus® database). Subjects vaccinated with QIVc or QIVe-SD from 8/2017–1/2018 were identified (date of vaccination termed the index date). Influenza-related hospitalizations/ER visits, all-cause hospitalizations and serious respiratory hospitalizations/ER visits were assessed post-vaccination. Inverse probability of treatment weighting (IPTW) and Poisson regression were used to evaluate the adjusted rVE of QIVc compared to QIVe-SD. In a subgroup analysis, rVE was assessed for several subgroups of interest (4–17, 18–64 and 50–64 years, and subjects with ≥1 high-risk condition). In a secondary economic analysis, annualized all-cause costs over the follow-up were compared using propensity score matching (PSM) and generalized estimating equation (GEE) models.ResultsThe study sample comprised 555,538 QIVc recipients and 2,528,524 QIVe-SD recipients. Prior to adjustment, QIVc subjects were older and had higher total costs in the 6-months pre-index. Following IPTW-adjustment and Poisson regression, QIVc was more effective in reducing influenza-related hospitalizations/ER visits, all-cause hospitalizations, and hospitalizations/ER visits related to asthma/COPD/bronchial events and other respiratory events compared to QIVe-SD. Similar trends were generally observed in the subgroup analysis. Following PSM adjustment and GEE regression, QIVe-SD was associated with significantly higher annualized all-cause total costs compared to QIVc, driven by higher costs for outpatient medical services and inpatient hospitalizations.ConclusionsAfter adjustment for confounders and selection bias, QIVc reduced influenza-related hospitalizations/ER visits, all-cause hospitalizations, and serious respiratory hospitalizations/ER visits compared to QIVe-SD. QIVc was associated with significantly lower all-cause total costs.     

Does consecutive influenza vaccination reduce protection against influenza: A systematic review and meta-analysis

IntroductionVaccination against influenza on an annual basis is widely recommended, yet recent studies suggest consecutive vaccination may reduce vaccine effectiveness (VE).PurposeTo assess whether when examining the entirety of existing data consecutive influenza vaccination reduces VE compared to current season influenza vaccination.Data sourcesMEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to April 26, 2017; citations of included studies.Study selectionRandomized, controlled trials (RCTs) and observational studies of children, adults and/or the elderly that reported laboratory-confirmed influenza infection over 2 or more consecutive influenza seasons were eligible.Data extractionData related to study characteristics, participant demographics, cases of influenza infection by vaccination group and risk of bias assessment was extracted in duplicate.Data synthesisFive RCTs involving 11,987 participants did not show a significant reduction in VE when participants vaccinated in two consecutive seasons (VE 71%, 95% CI 62–78%) were compared to those vaccinated in the current season (VE 58%, 95% CI 48–66%) (odds ratio [OR] 0.88, 95% CI 0.62–1.26, p = 0.49, I² = 39%). Twenty-eight observational studies involving 28,627 participants also did not show a reduction (VE for two consecutive seasons 41%, 95% CI 30–51% compared to VE for current season 47%, 95% CI 39–54%; OR 1.14, 95% CI 0.98–1.32, p = 0.09, I² = 63%). Results from subgroup analyses by influenza type/subtype, vaccine type, age, vaccine match and co-morbidity support these findings; however, dose–response results were inconsistent. Certainty in the evidence was assessed to be very low due to unexplained heterogeneity and imprecision.LimitationsThe inclusion of studies with relatively small sample sizes and low event rates contributed to the imprecision of summary VE and OR estimates, which were based on unadjusted data.ConclusionAvailable evidence does not support a reduction in VE with consecutive influenza vaccination, but the possibility of reduced effectiveness cannot be ruled out due to very low certainty in this evidence.Funding sourceCIHR Foundation Grant (PROSPERO: CRD42017059893).     

Relative effectiveness of high dose versus standard dose influenza vaccines in older adult outpatients over four seasons, 2015–16 to 2018–19

BackgroundNew influenza vaccine formulations are designed to improve vaccine effectiveness and protect those most vulnerable to infection. High dose trivalent inactivated influenza vaccine (HD-IIV3), licensed for ages ≥65 years, produces greater antibody responses and efficacy in clinical trials, but post-licensure vaccine effectiveness (VE) compared to standard dose (SD-IIV3/4) vaccine remains an open question.MethodsUsing a test-negative, case control design and propensity analyses to adjust for confounding, US Influenza VE Network data from the 2015–2016 through 2018–2019 seasons were analyzed to determine relative VE (rVE) between HD-IIV3 and SD-IIV3/4 among outpatients ≥65 years old presenting with acute respiratory illness. Influenza vaccination status was derived from electronic medical records and immunization registries.ResultsAmong 3861 enrollees, 2993 (78%) were vaccinated; 1573 (53%) received HD-IIV3 and 1420 (47%) received SD-IIV3/4. HD-IIV3 recipients differed from SD-IIV3/4 recipients by race, previous vaccination, number of outpatient visits in the previous year and timing of vaccination, and were balanced in the propensity model except the timing of vaccination. Compared with no vaccination, significant protection against any influenza A was observed from both HD-IIV3 (VE = 29%; 95%CI = 10%, 44%) and SD-IIV3/4 (VE = 24%; 95%CI = 5%, 39%); rVE = 18% (95%CI = 0%, 33%, SD as referent). When stratified by virus type, against A/H1N1, HD-IIV3 VE was 30% (95%CI = −7%, 54%), SD-IIV3/4 VE was 40% (95%CI = 10%, 61%), and rVE = −32%; (95%CI = −94%, 11%); Against A/H3N2, HD-IIV3 VE was 31% (95%CI = 9%, 47%), SD-IIV3/4 VE was 19% (95%CI = −5%, 37%), and rVE = 27%; (95% CI = 9%, 42%).ConclusionsAmong adults ≥65 years of age, recipients of standard and high dose influenza vaccines differed significantly in their characteristics. After adjusting for these differences, high dose vaccine offered more protection against A/H3N2 and borderline significant protection against all influenza A requiring outpatient care during the 2015–2018 influenza seasons.