Prevalence of influenza vaccination and associated factors among pregnant women in Hong Kong

A total of 568 pregnant women in Hong Kong were interviewed. Of them, 85.4% had heard of influenza vaccine, 21.3% had ever been vaccinated, 3.9% self-reported receiving influenza vaccination (IV) in the 2005/2006 flu season, and 33% were inclined toward receiving IV in the coming year. Multivariate analysis showed that those who had been recommended by health care professionals to receive IV during pregnancy were more likely than others to have received IV. Other variables related to the Health Belief Model were significantly associated with having ever been vaccinated or inclined toward receiving IV in the coming year.     

Factors associated with vaccination status among Korean submariners who are eligible for free non-mandatory influenza vaccination

IntroductionSubmarine crews live in a confined setting and are vulnerable to influenza. Thus, it would be useful to identify factors that are associated with influenza vaccination. In this study, we investigated the influenza vaccination rate and the influence of health beliefs on the vaccination rate among submariners who were eligible for a free but non-mandatory vaccination program.MethodsA total of 487 Korean submariners participated in this study after the closing of a free influenza vaccination program in 2015. Data regarding the participants’ general characteristics and health beliefs (based on the health belief model [HBM]) were collected using a self-administered questionnaire, and their vaccination status was determined using their medical records. Multiple logistic regression analysis were performed to evaluate the associations of the HBM components with influenza vaccination.ResultsThe overall vaccination rate was 78% (921/1183). The unvaccinated and vaccinated respondents exhibited similar characteristics, although the vaccinated group was significantly more likely to have high-risk family members (chronic disease, age of <2 years, or age of ⩾65 years; p = 0.025). Among the HBM components, perceived severity (odds ratio: 1.38, p = 0.019) and cue to action (odds ratio: 1.74, p = 0.002) were significantly associated with a higher likelihood of influenza vaccination.ConclusionVaccination policies that emphasize the severity of influenza and prompt individuals to undergo vaccination are needed to increase the vaccination rate among people who live in confined environments or institutions with non-mandatory vaccination programs.     

Vaccination strategies to protect children against seasonal and pandemic influenza

To protect children against infection with seasonal influenza viruses, this age group is vaccinated annually in some countries. However, currently used inactivated seasonal influenza vaccines do not protect well against antigenically distinct pandemic influenza virus strains. Furthermore, annual vaccination may prevent infection with seasonal influenza viruses and subsequently the induction of heterosubtypic immunity. Therefore, the development of influenza vaccines that induce broad protective immunity should be considered a priority. In the absence of such vaccines children that are vaccinated annually against seasonal influenza should in a pandemic scenario also receive pandemic vaccines as soon as these become available. In order to protect young infant under six months of age for which no vaccines are registered at present, vaccination of pregnant women should be considered. This would afford protection through maternally derived antibodies. In addition, vaccination of close family members of young infants is recommended, to prevent transmission within the household.     

Factors affecting the willingness of nursing students to receive annual seasonal influenza vaccination: A large-scale cross-sectional study

Nursing students are at high risk of exposure to vaccine-preventable diseases such as seasonal influenza. However, due to the limited number of studies conducted in this area, the prevalence and factors affecting annual seasonal influenza vaccination (ASIV) uptake remain unclear. This was a large-scale cross-sectional survey study conducted among 902 nursing students in different years of study. The questionnaire was developed based on the Health Belief Model (HBM), and logistic regression was used to determine the predictors of ASIV uptake. The results of our study reveal that only 15.2% of nursing students declared having the vaccine in the previous year, and that ASIV uptake was self-reported. ASIV uptake was associated with perceived susceptibility (odds ratio = 2.76), perceived seriousness (odds ratio = 2.06) and perceived barriers (odds ratio = 0.50). The odds of receiving ASIV were 17.96 times higher for those participants having had ASIV at least once than those who had not received ASIV in the previous five years. In addition, the odds of receiving ASIV were 4.01 times higher for master’s than undergraduate students. Our study concludes that the ASIV uptake among nursing students is low. In order to increase vaccination uptake in subsequent years, future studies should promote vaccination based on HBM, focusing on nursing students in undergraduate studies by emphasizing not only vaccination knowledge, but also their social responsibility to protect patients. Influenza vaccination can be viewed as an ethical professional responsibility and a patient safety issue, as well as being an infection control strategy.     

Determinants of influenza vaccination among young Taiwanese children

ObjectiveAccording to the Health Belief Model (HBM), individual perceptions of susceptibility, severity, benefit, barrier, self-efficacy, and cues to action are associated with health actions. In this study, we investigated the perceptions and social factors that influence the intention to vaccinate children against influenza among parents of young Taiwanese children.MethodsA nationwide survey was performed using stratified random sampling to explore the beliefs, attitudes, and intentions of parents/main caregivers with regard to vaccinating children aged 6 months to 3 years against influenza. A questionnaire was developed based on the HBM and multivariate logistic regression analyses of 1300 eligible participants were used to identify significant predictors of the intention to vaccinate.ResultsGreater perceived benefit, cues to action, and self-efficacy of childhood vaccination against influenza were positively associated with the intention to vaccinate. Children's experience of influenza vaccinations in the past year was also a positive predictor. However, perceived susceptibility, perceived severity regarding influenza and perceived barriers to vaccination were not predictive of the intention to vaccinate.ConclusionIn addition to perceived benefits and cues to action, self-efficacy of parents/main caregivers was significantly predictive of their intention to accept influenza vaccination for their young children. These components of the HBM could be used in formulating strategies aimed at promoting the use of influenza vaccine.     

Parental perceptions of childhood seasonal influenza vaccination in Singapore: A cross-sectional survey

PurposeSeasonal influenza vaccination is recommended in children aged 6–59 months, but little is known about child vaccination coverage and determinants in Asian settings. We report the results of a survey of knowledge, attitudes, practices, and determinants of child influenza vaccination in Singapore.MethodsIn December 2015-March 2016, we conducted a survey of 332 parents of children aged 6 months to 5 years attending pre-schools. We assessed child influenza vaccine coverage and parental knowledge, attitudes, and practices of child influenza vaccination. We used multivariable regression and structural equation models to identify factors associated with child influenza vaccination.ResultsKnowledge about influenza, perceived benefit of vaccination, and willingness to vaccinate were high. However, only 32% of children had ever received influenza vaccine, and only 15% in the past year. Factors independently associated with child influenza vaccination included: being recommended influenza vaccine by a child’s doctor (prevalence ratio (PR) = 2.47, 95% CI: 1.75–3.48); receiving influenza vaccine information from a private general practitioner (PR = 1.47, 95% CI: 1.05–2.04); regularly receiving pre-travel influenza vaccine (PR = 1.64, 95% CI: 1.19–2.25); higher willingness to vaccinate (PR = 1.58, 95% CI:1.24–2.04 per unit increase in willingness score); and feeling well-informed about influenza vaccine (PR = 1.44, 95% CI: 1.04–1.99). Parents who obtained influenza vaccine information from television were less likely to have vaccinated their child (PR = 0.44, 95% CI: 0.23–0.85). Path analysis indicated that being recommended vaccination by a child's doctor increased willingness to vaccinate and self-efficacy (feeling well-informed about influenza vaccine). Median willingness-to-pay for a dose of influenza vaccine was SGD30 (interquartile range: SGD20-SGD50), and was higher in parents of vaccinated compared with unvaccinated children (SGD45 vs SGD30, p = 0.0012).ConclusionKnowledge and willingness to vaccinate was high in this parent population, but influenza vaccine uptake in children was low. Encouraging medical professionals to recommend vaccination of eligible children is key to improving uptake.     

Economics of employer-sponsored workplace vaccination to prevent pandemic and seasonal influenza

Employers may be loath to fund vaccination programs without understanding the economic consequences. We developed a decision analytic computational simulation model including dynamic transmission elements that estimated the cost–benefit of employer-sponsored workplace vaccination from the employer's perspective. Implementing such programs was relatively inexpensive (<$35/vaccinated employee) and, in many cases, cost saving across diverse occupational groups in all seasonal influenza scenarios. Such programs were cost-saving for a 20% serologic attack rate pandemic scenario (range: −$15 to −$995) per vaccinated employee) and a 30% serologic attack rate pandemic scenario (range: −$39 to −$1,494 per vaccinated employee) across all age and major occupational groups.     

Influenza vaccination effectiveness in preventing influenza hospitalization in children,Hong Kong,winter 2019/20

The winter influenza season 2019/20 in Hong Kong was predominated by influenza A(H1N1)pdm09. We analysed an on-going test-negative design study consisting of 1227 children admitted for febrile acute respiratory illness from 3 November 2019 (week 45) to 21 March 2020 (week 12). We estimated influenza vaccine effectiveness of 65% (95% CI: 46 – 78) against hospitalization due to influenza A and B combined, and 74% (95% CI: 54 – 85) against hospitalization due to influenza A(H1N1)pdm09.     

Intention to receive influenza vaccination prior to the summer influenza season in adults of Hong Kong, 2015

Following a severe winter epidemic of drifted influenza A(H3N2) during January–March 2015, the Hong Kong government purchased vaccines of southern hemisphere formulation for administration prior to the anticipated summer influenza epidemic. This is the first time that seasonal influenza vaccines will be delivered twice within the same year in Hong Kong. We conducted a household telephone survey to investigate the acceptance of Hong Kong adults to pre-summer influenza vaccination. We found that the proportion of people reporting intention to receive vaccination was 37.8, 24.0, 31.4, and 34.4% in the age groups of 18–39, 40–59, 60–69, and 70 years or above. Only 31.3% of respondents who claimed they were parents or guardians said they would take their children to receive vaccination if the new vaccine was available. These findings suggested that intention to receive pre-summer vaccination was low even among the priority group of older people.     

HPV vaccination among a community sample of young adult women

Objectives

Despite the high efficacy of the human papillomavirus (HPV) vaccine, uptake has been slow and little data on psychosocial barriers to vaccination exist.

Methods

A community sample of 428 women enrolled in a longitudinal study of social development in the Seattle WA metropolitan area were interviewed about HPV vaccine status, attitudes, and barriers to HPV vaccination in spring 2008 or 2009 at ∼age 22.

Results

Nineteen percent of women had initiated vaccination, 10% had completed the series, and ∼40% of unvaccinated women intended to get vaccinated. Peer approval was associated with vaccine initiation (adjusted prevalence ratio (APR) 2.1; 95% confidence interval 1.4-3.2) and intention to vaccinate (APR 1.4; 1.1-1.9). Belief the vaccine is <75% effective was associated with less initiation (APR 0.6; 0.4-0.9) or intention to vaccinate (APR 0.5; 0.4-0.7). Vaccine initiation was also less likely among cigarette smokers and illegal drug users, whereas intention to vaccinate was more common among women currently attending school or with >5 lifetime sex partners, but less common among women perceiving low susceptibility to HPV (APR 0.6; 0.5-0.9).

Conclusions

HPV vaccination uptake was low in this community sample of young adult women. Increasing awareness of susceptibility to HPV and the high efficacy of the vaccine, along with peer interventions to increase acceptability, may be most effective.     

Factors affecting parental intention to vaccinate kindergarten children against influenza: A cross-sectional survey in China

Background

The impact of influenza in children under 5 can be severe and fatal. However, the influenza vaccination uptake in China remains suboptimal. The objectives of this study were to investigate parents’ perceptions on influenza vaccination and to assess vaccination promotional factors.

Changing the default to promote influenza vaccination among health care workers

BackgroundThe prevention of health care acquired infections is an important objective for patient safety and infection control in all health care settings. Influenza vaccination uptake among health care workers (HCWs) is the most effective method to prevent transmission to patients, but vaccination coverage rates are low among HCWs. Several educational campaigns have been developed to increase the influenza vaccination coverage rates of HCWs, but showed only small effects. The aim of this study was to test an opt-out strategy in promoting uptake among HCWs in a tertiary care center for patients with complex chronic organ failure.MethodsHCWs were randomly assigned to one of two conditions. In the opt-out condition (N = 61), participants received an e-mail with a pre-scheduled appointment for influenza vaccination, which could be changed or canceled. In the opt-in condition (N = 61), participants received an e-mail explaining that they had to schedule an appointment if they wanted to get vaccinated.ResultsThe findings show no statistically detectable effect of condition on being vaccinated against influenza. However, HCWs in the opt-out condition were more likely to have an appointment for influenza vaccination, which in turn increased the probability of getting vaccinated.ConclusionTo change the default to promote influenza vaccination among HCWs might be an easy and cost-effective alternative to the complex vaccination campaigns that have been proposed in recent years.     

Communication-based interventions for increasing influenza vaccination rates among Aboriginal children: A randomised controlled trial

BackgroundIn Australia, the influenza vaccine is funded for Aboriginal and Torres Strait Islander (hereafter referred to as Aboriginal) children aged 6 months to <5 years old. In Victoria, only 2% of Aboriginal children are vaccinated against influenza.ObjectiveTo evaluate whether sending a letter or sending a pamphlet directly to parents/guardians would improve influenza vaccine uptake amongst Aboriginal identified children.DesignThe study involved a multi-arm, parallel, randomised controlled trial with two intervention groups and one control group.Participants & settingParticipants included parents or guardians of Victorian children (aged 6 months to <5 years) who identified as Aboriginal. Households (n = 5534) were randomised (using a random number generator) to receive either a personalised letter (n = 1845), a pamphlet (n = 1845), or no direct communication (control) (n = 1844). The letter and the pamphlet were designed using the INSPIRE framework – a set of behaviour change techniques for action-oriented communication.Main outcome measureThe proportion of households where all eligible children received the influenza vaccine between 2 May 2017 and 1 September 2017.ResultsThe control group’s vaccination rate was 4.4%, higher than previous years. The pamphlet group achieved a similar vaccination rate (4.5%). The letter group’s vaccination rate of 5.9% was significantly higher than the control group [χ² (1, n = 3689) = 4.33, p = .037].ConclusionsSending a personalised letter directly to parents/guardians was an effective strategy for increasing influenza vaccination among Aboriginal children. The ineffectiveness of the pamphlet may be due to the lack of personalisation and the authority associated with the letter. Additional research is required to understand participant responses to the material.Trial registrationThis research was retrospectively registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) on 13 September 2017 (ACTRN12617001315303).     

Cost-effectiveness and socio-economic aspects of childhood influenza vaccination

Children have high rates of healthcare utilization due to influenza. In addition, children also transmit influenza to others in their households and the community. The costs of influenza in children include the direct medical care costs from increased outpatient visits and hospitalizations, and also indirect costs due to productivity losses especially for their parents and due to transmission of the virus to others. A variety of studies using different methods and assumptions have assessed the cost-effectiveness of influenza vaccination of children, and many find that vaccination is either cost saving or cost effective.     

Prevalence of influenza vaccination and associated factors among community-dwelling Hong Kong residents of age 65 or above

A total of 877 Hong Kong Chinese community-dwelling elderly were telephone-interviewed. Of them, 63.2% had heard of influenza vaccination (IV), 31.2% had ever had IV (of which 93.3% did so in the last 6 months) and 51.4% were inclined toward receiving free IV in the coming year. Multivariate analyses showed that older age, perceptions of side effects, perceptions of effectiveness duration, and knowing where to get vaccinated were significantly associated with having ever been vaccinated. These variables are related to the Health Belief Model. The prevalence of IV appeared to be increasing as a result of the recent SARS epidemic.     

上海市静安区社区医务人员流感疫苗接种率及其影响因素

目的 了解上海市静安区社区医务人员流感疫苗接种率及其影响因素.方法 2019年4月,对上海市静安区共15家社区卫生服务中心的所有医务人员进行问卷调查,采用x2检验和多因素Logistic回归分析模型对流感疫苗接种率的影响因素进行单因素和多因素分析.结果 上海市静安区社区医务人员流感疫苗接种率为14.57％,多因素Log...     

中国流感疫苗预防接种技术指南(2018-2019)

接种流感疫苗是预防流感病毒感染及其并发症的最有效手段。目前,我国国内批准上市的灭活流感疫苗为三价（ⅡV3）和四价（ⅡV4）疫苗,包括裂解疫苗和亚单位疫苗。流感疫苗在我国大多数地区属于第二类疫苗,实行自愿、自费接种。为指导我国流感预防控制和疫苗应用工作,中国CDC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,对2014年版指南进行了更新和修订,形成了《中国流感疫苗预防接种技术指南（2018－2019）》。本指南主要更新了以下内容：流感的流行病学和疾病负担,流感疫苗的种类、2018－2019年度流感疫苗抗原组份、ⅡV3和ⅡV4疫苗的免疫反应、免疫持久性、免疫原性、效力、效果、安全性、成本效果和成本效益等;并基于现有的科学证据,提出了2018－2019年度流感疫苗预防接种的建议。本指南建议：原则上,接种服务单位应为≥6月龄所有愿意接种流感疫苗且无禁忌证的人提供接种服务。对可接种不同类型、厂家疫苗产品的人群,可由受种者自愿选择接种任一种流感疫苗,无优先推荐。为降低高危人群罹患流感及感染后发生严重临床结局的风险,指南推荐6月龄至5岁儿童、≥60岁老年人、慢性病患者、医务人员、<6月龄婴儿的家庭成员和看护人员以及孕妇或准备在流感季节怀孕的女性为优先接种对象;首次接种流感疫苗的6月龄至8岁儿童应接种2剂次,间隔≥4周;2017－2018年度或以前接种过≥1剂次流感疫苗的儿童,建议接种1剂次;≥9岁儿童和成年人仅需接种1剂次。建议各地防疫部门在疫苗供应到位后尽快安排接种工作,最好在10月底前完成免疫接种;对10月底前未接种的对象,整个流行季节都可以提供接种服务;孕妇在孕期的任一阶段均可接种流感疫苗。本指南适用于从事流感防控相关的各级CDC工作人员,预防接种点的接种人员,各级医疗机构儿科、内科、感染科等医务人员,以及各级妇幼保健机构的专业人员。     

中国流感疫苗预防接种技术指南（2019-2020）

流行性感冒（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可发生暴发疫情。每年流感季节性流行在全球可导致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。接种流感疫苗是预防流感病毒感染及其严重并发症的最有效手段。我国现已批准上市的流感疫苗有三价灭活流感疫苗（IIV3）和四价灭活流感疫苗（IIV4）,IIV3包括裂解疫苗和亚单位疫苗,IIV4为裂解疫苗。除个别地区外,流感疫苗在我国大多数地区属于第二类疫苗,实行自愿、自费接种。2018年,中国疾病预防控制中心印发了《中国流感疫苗预防接种技术指南（2018-2019）》（2018年版指南）。一年来,新的研究证据在国内外发表,新的疫苗产品在我国上市。为更好的指导我国流感预防控制和疫苗应用工作,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2018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（2019-2020）》。本指南更新的内容主要包括以下几个方面：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、接种疫苗可避免的疾病负担、疫苗安全性监测、疫苗预防接种成本效果等;第二,增加了一年来国家卫生健康委员会流感防控有关政策和措施;第三,更新了我国2019-2020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IIV3和IIV4疫苗组份。本指南建议：原则上,接种服务单位应为≥ 6月龄所有愿意接种流感疫苗且无禁忌证的人提供接种服务。对可接种不同类型、厂家疫苗产品的人群,可由受种者自愿选择接种任一种流感疫苗,无优先推荐。为降低高危人群罹患流感及感染后发生严重临床结局的风险,指南推荐6月龄至59月龄儿童、≥ 60岁老年人、慢性病患者、医务人员、<6月龄婴儿的家庭成员和看护人员以及孕妇或准备在流感季节怀孕的女性为优先接种对象。首次接种流感疫苗的6月龄至8岁儿童应接种2剂次,间隔≥ 4周;2018-2019年度或以前接种过≥ 1剂次流感疫苗的儿童,建议接种1剂次。≥ 9岁儿童和成年人仅需接种1剂次。建议各地疾控机构在疫苗供应到位后尽快安排接种工作,最好在10月底前完成免疫接种;对10月底前未接种的对象,整个流行季节都可以提供接种服务。孕妇在孕期的任一阶段均可接种流感疫苗。本指南适用于从事流感防控相关的各级CDC工作人员,预防接种点的接种人员,各级医疗机构儿科、内科、感染科等医务人员,以及各级妇幼保健机构的专业人员。根据国内外研究进展,本指南今后亦将定期更新、完善。