流感疫苗，你问我答

流行性感冒（简称流感）常呈暴发流行。由于至今对流感无有效的治疗方法，因此现在流感疫苗的接种仍然是预防流感的主要措施，尤其对一些易患流感的高危人群，疫苗的接种能降低发病率和减少并发症。但是每到流感疫苗接种季节，由于对流感疫苗的不了解，我们常常要做大量的解释工作，这里不妨写出来，更加方便读者朋友。     

中国医疗机构工作人员流感疫苗预防接种指南

为了加强中国医疗机构工作人员流感疫苗的接种, 中华预防医学会医院感染控制分会联合中国临床实践指南联盟制定了《中国医疗机构工作人员流感疫苗预防接种指南》。本指南结合国内外研究进展和专家意见, 主要关注了7个临床相关问题, 并根据牛津循证医学中心2011版证据质量评估表对研究进行证据评级, 最终形成推荐意见。指南强调了医疗机构工作人员接种流感疫苗的重要性, 降低自身流感患病率可有效减少医院传播风险。本指南建议: 如无禁忌证, 医疗机构工作人员均应积极接种流感疫苗。推荐对感染传播风险极高的工作人员、高危人群和孕妇优先接种流感疫苗。另外, 指南还提供了疫苗的选择、接种时间及接种频次的建议。鉴于目前我国医疗机构工作人员流感疫苗接种率偏低且地区差异明显, 本指南建议进一步加强关于流感疫苗接种的健康教育, 根据各个省市区具体情况, 采取"多元化"方法, 积极开展有组织的接种活动。     

孕妇流感疫苗接种相关研究进展

流感是由流感病毒引起的急性呼吸道传染病, 妊娠期间因生理和免疫功能的变化, 孕妇罹患流感及发生相关并发症的风险较高。接种流感疫苗是预防流感的有效手段。WHO和许多国家均将孕妇列为流感疫苗接种的优先推荐人群, 但目前我国孕妇流感疫苗接种率偏低, 且部分产品使用说明将孕妇列为接种禁忌人群, 推动孕妇流感疫苗接种工作仍存在诸多挑战。本文就近年来国内外流感对孕妇及其胎儿的影响以及孕妇接种流感疫苗研究进展进行综述, 并针对目前孕妇流感疫苗接种的现状, 提出促进孕妇接种流感疫苗的策略并进行探讨, 以期为我国相关工作的开展和政策制定提供参考。     

公众流感疫苗认知、接种现状及影响因素分析

目的 了解公众流感疫苗认知、接种现状及影响因素,为提高流感疫苗接种率提供科学依据。 方法 2020年1月15日—4月30日期间,使用12320公益电话平台,对广州、廊坊、南京、苏州、太原和重庆等6地区公众流感疫苗认知和2019—2020年流感季流感疫苗接种现状开展电话调查,采用多因素logistic回归模型分析影响不同年龄段公众流感疫苗接种率的相关因素。 结果 有效应答共计12 263人。2019—2020年流感季,16.34%(1 959/11 989)受访者曾咨询过流感疫苗接种事宜,流感疫苗接种比例为12.95%(1 529/11 810),其中6月龄~5岁儿童接种比例为26.84%(877/3 267),6~17岁学生为14.78%(245/1 658),18~59岁成年人为3.99%(199/4 989),≥60岁老年人为10.97%(208/1 896)。仅5.22%(202/3 866)受访者认为流感疫苗不安全,74.85%(3 785/5 057)认为流感疫苗具有中等和较好的保护效果。多因素logistic回归分析显示,免费接种、咨询流感疫苗接种、认为流感疫苗保护效果好、接种方便可促进流感疫苗的接种。 结论 公众对流感疫苗安全性和保护效果认可度较高,作为流感重症高危人群的5岁以下儿童和老年人需要进一步提升流感疫苗接种覆盖率。加大对流感疫苗相关知识宣传力度,提供便捷的咨询和接种服务可提高公众流感疫苗接种率。     

中国老年人群流感疫苗接种支持性环境演变及地区差异

季节性流感具有较高的疾病负担, 老年人感染流感后容易引起多种并发症。接种流感疫苗可有效预防感染并显著降低并发症和重症发生风险。提供疫苗接种相关支持性环境对提高老年人群流感疫苗接种率有着重要作用。在我国, 当前针对老年人群流感疫苗的支持性环境主要包括老年人群流感疫苗免费接种政策和费用报销政策等, 不同城市或地区间存在显著的地区差异。本研究对我国老年人群流感疫苗接种相关的支持性环境和地区差异进行系统梳理, 以了解当前流感疫苗接种的背景环境带来的流感防控机会和地区差异可能导致的健康不平等挑战, 为国家相关政策和民生项目的出台提供科学参考。     

积极应对季节性流感： ２０１６年全国季节性流感防控研讨会会议纪要

摘要：２０１６年７月３０～３１日和８月６～７日，中华预防医学会先后在江苏南京和四川成都举办了“２０１６年 全国季节性流感防控研讨会”。会议报告了全球和我国季节性流感（简称“流感”）防控策略和进展，梳理 了我国流感面临的形势，解读了世界卫生组织接种流感疫苗的立场文件，展示了流感优先接种人群的流感 疾病负担及流感疫苗接种效果，并重点针对儿童、老年人和慢性病患者的流感防控证据和经验进行了深入 的交流。会议认为，我国流感疾病负担较重，疫苗接种是预防流感最有效的方式；５ 岁以下儿童、老年人 和慢性病患者是流感的高危人群，感染流感病毒后发生重症和死亡的风险较高；学龄儿童的流感罹患率最 高，是家庭和社区流感的主要传播者。会议强调，校园流感防控应注重“卫教联手”；医务人员的疫苗接种 推荐是提高老年人和慢性病患者流感疫苗接种率的重要途径。 关键词：季节性流感；防控策略；免疫接种 中图分类号：Ｒ１８３　　文献标识码：Ａ　　文章编号：１００９ ６６３９ （２０１６）０９ ０６４１ ０５     

学龄前儿童家长流感认知情况与流感疫苗接种意愿调查

目的了解学龄前儿童家长对流感认知情况及流感疫苗接种意愿,为流感防控工作提供科学依据。方法采用分层抽样方法对新乡医学院第三附属医院免疫接种门诊管理的学龄前儿童家长进行问卷调查。结果共调查340名家长,58.53%的家长不清楚流感与普通感冒的区别。63.82%的家长表示会为孩子接种流感疫苗,97.06%的家长希望流感疫苗作为第一类疫苗由政府免费提供。Logistic回归分析,儿童家长文化程度高、孩子曾经患流感、孩子曾经接种流感疫苗的家长更愿意接种流感疫苗。结论今后应加强对流感疾病相关知识宣教,对流感疫苗的宣讲应具有针对性,加大对疫苗安全性、保护效果、预防人群的宣讲力度,提高流感疫苗接种率。     

中国流感疫苗预防接种技术指南（2022-2023）

流感是由流感病毒引起的一种急性呼吸道传染病,严重危害人群健康。流感病毒其抗原性易变,传播迅速,每年可引起季节性流行,在学校、托幼机构和养老院等人群聚集的场所易发生暴发疫情。每年季节性流感流行在全球可导致300万~500万重症病例,29万~65万呼吸道疾病相关死亡。孕妇、婴幼儿、老年人和慢性基础疾病患者等高危人群,患流感后出现严重疾病和死亡的风险较高。尤其是全球新型冠状病毒肺炎（新冠肺炎）疫情严重流行态势仍在持续,今年我国南方部分省份出现夏季流感流行高峰,今冬明春可能会出现新冠肺炎与流感等呼吸道传染病叠加流行的情况。接种流感疫苗是预防流感、减少流感相关重症和死亡的有效手段,可以减少流感相关疾病带来的健康危害及对医疗资源的挤兑。我国现已批准上市的流感疫苗有三价灭活流感疫苗（IIV3）、四价灭活流感疫苗（IIV4）和三价减毒活流感疫苗（LAIV3）,IIV3包括裂解疫苗和亚单位疫苗,IIV4为裂解疫苗,LAIV3为减毒疫苗。流感疫苗在我国属于非免疫规划类疫苗,居民自愿接种。2018年以来,中国疾病预防控制中心每年印发当年度的《中国流感疫苗预防接种技术指南》。一年来,新的研究证据在国内外发表,为更好地指导我国流感预防控制和疫苗接种工作,国家免疫规划技术工作组流感疫苗工作组综合国内外最新研究进展,在2021年版指南的基础上进行了更新和修订,形成了《中国流感疫苗预防接种技术指南（2022-2023）》。本指南更新的内容主要包括：第一,增加了新的研究证据,尤其是我国的研究结果,包括流感疾病负担、疫苗效果、疫苗安全性监测、疫苗预防接种成本效果等;第二,更新了一年来国家出台的有关流感防控政策和措施;第三,更新了2022-2023年度国内批准上市及批签发的流感疫苗种类;第四,更新了本年度三价和四价流感疫苗组分;第五,更新了2022-2023年度的流感疫苗接种建议。本指南建议：原则上,接种单位应为≥6月龄所有愿意接种流感疫苗且无接种禁忌的人提供接种服务。≥18岁的人群可在一次接受免疫服务时,在两侧肢体分别接种灭活流感疫苗和新型冠状病毒疫苗（新冠疫苗）;<18岁的人群,建议流感疫苗与新冠疫苗接种间隔仍>14 d。对可接种不同类型或不同厂家疫苗产品的人群,可由受种者自愿选择接种任何一种流感疫苗,无优先推荐。结合今年新冠肺炎疫情形势,为尽可能降低流感的危害和对新冠肺炎疫情防控的影响,优先推荐以下重点和高风险人群及时接种：①医务人员,包括临床救治人员、公共卫生人员、卫生检疫人员等;②大型活动参加人员和保障人员;③养老机构、长期护理机构、福利院等人群聚集场所脆弱人群及员工;④重点场所人群,如托幼机构、中小学校的教师和学生,监所机构的在押人员及工作人员等;⑤其他流感高风险人群,包括≥60岁居家老年人、6月龄至5岁儿童、慢性病患者、6月龄以下婴儿的家庭成员和看护人员以及孕妇。对于IIV,6月龄至8岁儿童首次接种流感疫苗的应接种2剂次,间隔≥4周;2021-2022年度或以前接种过1剂次或以上流感疫苗的儿童,建议接种1剂次;≥9岁儿童和成年人仅需接种1剂次。对于LAIV,无论是否接种过流感疫苗,仅接种1剂次。建议各地在疫苗供应到位后尽早开展接种工作,尽量在当地流感流行季前完成接种。同一流行季,已按照接种程序完成全程接种的人员,无需再次接种。孕妇在孕期的任一阶段均可接种灭活流感疫苗。接种单位在整个流行季节都可以提供接种服务。本指南适用于疾控机构、医疗机构、妇幼保健机构和接种单位等从事流感防治相关的专业人员。根据国内外研究进展,本指南今后亦将定期更新、完善。     

肺炎疫苗、流感疫苗联合接种对老年慢性病人群呼吸系统疾病的干预价值

目的 探讨肺炎疫苗、流感疫苗联合接种对老年慢性病人群呼吸系统疾病的干预价值。方法 选取2022年1—12月本院收治的87例老年慢性病患者作为研究对象,用随机数字表法将其分为肺炎疫苗接种组（29例）、流感疫苗接种组（29例）、联合接种组（29例）,对比三组患者接种后就诊和住院情况、流感及肺炎发生状况。结果 肺炎疫苗接种组和流感疫苗接种组感染率、病死率高于联合接种组（P<0.05）;观察组症状持续时间、住院时间短于对照组,住院次数低于对照组（P<0.05）;联合接种组不良反应发生率低于肺炎疫苗接种组、流感疫苗接种组（P<0.05）。结论 老年慢性病人群接受肺炎疫苗、流感疫苗联合接种,能明显降低疾病的发生,缩短住院时间,并有效防控流感、肺炎发病,有推广应用价值。     

西南某市未接种流感疫苗老年人群的知信现状与接种意愿的影响因素研究

目的 了解目前西南某市未接种流感疫苗老年人群对流感疫苗的知信现状和接种意愿,分析影响该老年人群接种意愿的因素,为推进流感疫苗普及提供依据。方法 收集某市2023年10—12月600例60岁及以上未接种流感疫苗的老年人对流感疫苗相关知识的知信现状与接种意愿,最终有效问卷538份。采用t检验和χ2检验进行单因素分析,流感疫苗接种意愿的多因素分析采用logistic回归模型。结果 538例老年人中57.8%的有流感疫苗接种意愿。55.6%的老年人“不了解或没有听说过流感疫苗”;53.2%的老年人认为“流感疫苗可能没有效果”;67.5%的老年人认为“接种流感疫苗会产生副作用”,且“估计产生副作用的比例”为17.53%。流感疫苗接种意愿的多因素分析结果显示,与“没有听说过流感疫苗”组相比,“大致了解”者(OR=2.464, 95%CI:1.209～5.019, P=0.013)和“非常了解”者(OR=2.885, 95%CI:1.112～7.485, P=0.029)流感疫苗接种意愿高;与“估计60岁及以上老年人群流感疫苗的接种比例为<20%”组相比,“估计接种比例60%～80%”组(OR...     

高风险人群流感疫苗接种现况和免疫策略分析

流感是由流感病毒引起的一种呼吸道传染性疾病,严重疾病负担常见于高风险人群。接种流感疫苗是预防流感及其并发症的有效方法,尤其是对高风险人群。虽然已有部分国家将流感疫苗纳入国家免疫规划,但全球范围内高风险人群流感疫苗接种率仍然较低。目前,流感疫苗在我国仍属于自愿自费接种的非免疫规划疫苗,且全国各地流感疫苗免疫策略差异化明显,接种率与发达国家仍有差距。进一步优化我国流感疫苗全人群免疫策略,加强流感疫苗全人群免疫策略的宣传,降低我国流感的疾病负担,是目前迫切需要解决的问题。     

Acceptance and uptake of influenza vaccines in Asia: A systematic review

In Asia, the public health burden of influenza is significant despite the existence of efficacious influenza vaccines. Annual seasonal influenza vaccination can reduce the incidence of influenza significantly, yet influenza vaccination coverage remains low in this part of the world. As a densely populated region with varying climatic zones and a larger proportion of developing countries compared to the West, Asia is at increased risk of influenza. To provide a more comprehensive and nuanced understanding of the Asian region, the key objective of this systematic review is to examine the determinants of vaccination uptake in Asia, beyond that of existing studies that have largely been western-centric.We carried out a systematic review of peer-reviewed scientific research, examining the key determinants, acceptance and uptake of influenza vaccinations across Asia. A comprehensive search strategy was defined to capture studies that met the inclusion criteria of articles published in English, from 2008 to 2018, focusing on adult populations within Asia. A total of 83 relevant studies were appraised in this review. Analyses of the extant data confirmed that vaccination rates within Asia are low, and that most countries lack scientific research on vaccination behaviours. Studies were categorised into four different population groups: healthcare workers, high risk groups, general population and uniform groups. The motivators and deterrents for vaccine uptake varied according to population groups and characteristics. Both general populations and healthcare workers were concerned with vaccine safety and efficacy, and recommendations from health authorities were influential in vaccine uptake within the other populations.The findings suggest that further research is needed within a broader range of Asian countries to garner greater in-depth knowledge of vaccination behaviours in the region. In particular, influenza vaccination programs within Asia should focus on improving engagement more effectively, through greater relatability and transparency of data when educating the public.     

Vaccine-preventable influenza disease burden from clinical trials of Vaxigrip - an inactivated split virion influenza vaccine - supports wider vaccine use

Trivalent inactivated split influenza virus vaccine has been used for more than 35 years, and is currently licensed in over 100 countries. To determine vaccine-preventable influenza burden in different populations and geographic regions, we reviewed studies of vaccine effectiveness against non-specific outcomes such as upper respiratory infection, hospitalization, and death in addition to confirmed microbiologically confirmed influenza. The vaccine-preventable disease incidence was high in most studies, regardless of the outcome or population evaluated. This indicates that routine influenza vaccination can improve overall population health under a broad range of circumstances.     

Factors influencing the uptake of influenza vaccine vary among different groups in the hard‐to‐reach population

Objective : This report describes a mobile outreach influenza immunisation program for vulnerable populations in a resource‐rich setting. It explores vaccine recipients’ demographics, comorbidities and vaccination histories, and the factors influencing their decision to receive vaccine during outreach. Methods : Teams of nurse immunisers visited and provided influenza vaccines to clients from 21 sites (18 community centres for migrants, refugees and the homeless; and three outpatient clinics). Risk factors for severe influenza, vaccination histories and perceived barriers and facilitators to vaccines were collected from vaccine recipients. Results : A total of 1,032 vaccine recipients participated in the survey with responses collected from April to October 2018. Of these, 54% reported at least one risk factor for severe influenza. Sixty per cent of recipients had not received an influenza vaccine in 2017, with most of them reporting ‘not worried about influenza’ as a reason. Pregnant participants most frequently reported a healthcare provider’s recommendation as the reason to receive the vaccine. Conclusion : An outreach program comprising of a means of taking vaccines to the population was a successful strategy to deliver influenza vaccines to high‐risk populations. It needs to be considered in the full range of delivery models to improve influenza vaccine coverage, even in resource‐rich settings. Implication for public health : Strategies reaching out to vulnerable populations are crucial to maximise vaccine uptake.     

Determinants of uptake of influenza vaccination among pregnant women – A systematic review

Background

Pregnant women have the highest priority for seasonal influenza vaccine. However, suboptimal coverage has been repeatedly noted in this population. To improve vaccine uptake, reviewing the determinants of vaccination is of increasing importance.

Methods

A detailed literature search was performed up to November 30, 2013 to retrieve articles related to uptake of influenza vaccination during pregnancy.

Results

Forty-five research papers were included in the review. Twenty-one studies assessed the coverage of seasonal influenza vaccination, 13 studies assessed coverage of A/H1N1 pandemic vaccination and 11 studies assessed both. Vaccination uptake ranged from 1.7% to 88.4% for seasonal influenza, and from 6.2% to 85.7% for A/H1N1 pandemic influenza. Many pregnant women were unaware that they were at high risk for influenza and its complications during pregnancy. They were also more likely to underestimate the threat of influenza to themselves and their fetus. Moreover, they had substantial concerns about the safety and efficacy of the influenza vaccine during pregnancy. Negative media reports contributed to the perception that influenza vaccination during pregnancy was risky and could result in adverse pregnancy outcomes. Although health care providers’ (HCPs) recommendations were consistently associated with vaccine uptake, most did not recommend the vaccine to their pregnant clients.

Conclusions

Influenza vaccination uptake among pregnant women is suboptimal and HCPs rarely recommend it. Positive vaccination recommendations from HCPs as well as direct access to the vaccine would likely substantially improve vaccination acceptance.     

Estimating influenza vaccine effectiveness: Evolution of methods to better understand effects of confounding in older adults

Older adults are at high risk for serious complications of influenza illness and loss of vaccine-mediated protection. It is increasingly recognized that in addition to age, multiple chronic conditions and associated frailty contribute to the decline in vaccine effectiveness in this population. However, observational studies have been fraught with issues of confounding related to the degree of frailty and functional decline, measures of which are not included in standard administrative health care databases that are used to calculate vaccine effectiveness. This issue has led to the identification of confounding by indication or from “healthy vaccinee” bias, which respectively lead to underestimates or overestimates of influenza vaccine effectiveness. In addition, the sensitivity and specificity of the criteria used to define influenza-like illness declines with increasing age due to atypical presentations of illness and the inability to distinguish between influenza and other respiratory viruses. The test-negative case:control design has emerged as a method to estimate influenza vaccine effectiveness by comparing vaccination rates in those with laboratory-confirmed influenza to those with other acute viral respiratory illnesses. This review provides a perspective on how test-negative case:control study designs and new insights into mechanisms of protection have considerably strengthened influenza vaccination policy decisions for older adults that have historically been undermined by the conclusions of observational studies.     

Strategy for distribution of influenza vaccine to high-risk groups and children

Despite evidence that vaccinating schoolchildren against influenza is effective in limiting community-level transmission, the United States has had a long-standing government strategy of recommending that vaccine be concentrated primarily in high-risk groups and distributed to those people who keep the health system and social infrastructure operating. Because of this year's influenza vaccine shortage, a plan was enacted to distribute the limited vaccine stock to these groups first. This vaccination strategy, based on direct protection of those most at risk, has not been very effective in reducing influenza morbidity and mortality. Although it is too late to make changes this year, the current influenza vaccine crisis affords the opportunity to examine an alternative for future years. The alternative plan, supported by mathematical models and influenza field studies, would be to concentrate vaccine in schoolchildren, the population group most responsible for transmission, while also covering the reachable high-risk groups, who would also receive considerable indirect protection. In conjunction with a plan to ensure an adequate vaccine supply, this alternative influenza vaccination strategy would help control interpandemic influenza and be instrumental in preparing for pandemic influenza. The effectiveness of the alternative plan could be assessed through nationwide community studies.     

Prevalence and determinants of influenza vaccine coverage at tertiary pediatric hospitals

Despite long-standing recommendations, the uptake of influenza vaccination in children with high risk medical conditions is low. This study aimed to examine the uptake of influenza vaccination amongst a cohort of Australian children and factors associated with vaccine acceptance. Three hundred and sixteen parents of children attending outpatient clinics at the two pediatric hospitals in Sydney were recruited. The reported vaccination coverage rate was 41% among children with high risk conditions and 14% among standard risk children. There was a median of three clinic visits per high risk child at which an opportunity to vaccinate was apparently missed. Healthcare worker recommendation, having a high risk condition and parental beliefs about influenza and influenza vaccination were the most important determinants of vaccine uptake. Further studies on the beliefs and practices of doctors in this area will help guide interventions to improve vaccination rates in high risk children.     

Factors associated with uptake of seasonal and pandemic influenza vaccine among clinical risk groups in the UK: an analysis using the General Practice Research Database

Background

Influenza vaccine uptake rates are low compared with uptake rates of many other vaccines. It is unclear how this differs between risk groups in the population and between pandemic and non-pandemic influenza vaccines.

Aim

This study sought to estimate uptake rates of pandemic and seasonal influenza vaccines among clinical risk groups in the UK during the 2009/2010 influenza season and to identify predictors of vaccine uptake in this cohort.

Methods

Uptake rates were calculated using data from the UK General Practice Research Database (GPRD). Predictors of vaccination were identified using a modified Poisson regression with robust standard error estimates.

Results

Uptake of pandemic influenza vaccine in clinical risk groups was 40.3% and uptake of seasonal influenza vaccine was 61.3%. Factors found to be predictive of seasonal and pandemic influenza vaccination included age and the total number of underlying health conditions an individual had. At risk individuals in those age groups in which universal vaccination of the general population was recommended were more likely to have been vaccinated than individuals in age groups in which only clinical risk groups were recommended for vaccination; hence children in clinical risk groups were more likely to receive pandemic than seasonal influenza vaccine. In older people, having a history of Guillain Barré syndrome was associated with a reduced likelihood of receipt of both seasonal (IRR_adj 0.83, CI₉₅ 0.77–0.90) and pandemic influenza vaccines (IRR_adj 0.82, CI₉₅ 0.73–0.92).

Discussion

Uptake of pandemic influenza vaccine was lower than that of seasonal influenza vaccine among those at a clinically high risk of influenza related morbidity. This suggests that vaccination strategies may need to be altered during future pandemics. Recommending universal vaccination within age categories in which there is a large proportion of high risk individuals could be considered as this may result in higher uptake among clinical risk groups.     

Guillain-Barré syndrome and H1N1 (2009) pandemic influenza vaccination using an AS03 adjuvanted vaccine in the United Kingdom: self-controlled case series

In 1976 a swine influenza vaccine was associated with an increased risk of Guillain-Barré syndrome (GBS). Although subsequent studies did not find an increased risk of GBS following seasonal influenza vaccine, there was concern that the monovalent H1N1 vaccines developed against the swine influenza pandemic of 2009 might increase the risk of GBS. In the UK a split-virion AS03 oil-in-water adjuvanted vaccine (Pandemrix™) was predominantly used. To determine whether the risk of GBS increased after Pandemrix administration, we sought GBS cases during the period of vaccine use from neurologists and a patient support group, and following the vaccination period from hospital episode statistics (HES) in England. We obtained cases’ vaccination histories and illness onset dates from general practitioners. We determined the relative incidence of GBS in the 6 weeks after vaccination using the self-controlled case series method on the cases identified in HES. We included 327 GBS cases, of whom 37 received pandemic vaccine in the study period, nine of whom developed GBS within 6 weeks of vaccination (relative incidence 1.05 [95% confidence interval (CI) 0.37 to 2.24]). We found no evidence of an increased risk of GBS in the 6 weeks following pandemic influenza vaccination.