Investigating parental perceptions of side effects following vaccination

Background: One of the major factors contributing to parental refusal of vaccinations is the perception that vaccines cause side effects. Although symptoms are commonly reported following vaccinations, their causes are not always straightforward. Although some may be directly attributable to the vaccine itself, others may reflect pre-existing or coincidental symptoms that are misattributed to the vaccine.Purpose: To investigate psychological factors associated with parental report of side effects following vaccination with the child influenza vaccine, parental intention to re-vaccinate one’s child the following year, and actual rates of re-vaccination.Methods: A prospective cohort study was run in primary care practices in London in the 2016–17 influenza season (ClinicalTrials.gov number NCT02909855). Two hundred seventy parents from 14 practices completed a questionnaire before their child’s vaccination. Follow-up questionnaires were completed 3 days after vaccination and one month after vaccination. Parental report of side effects and vaccination intention for the subsequent year were measured. Re-vaccination was measured at the end of the 2017-18 influenza season.Results: Parental report of side effects was strongly associated with pre-vaccination expectation of side effects. Suggestions received from the media, National Health Service (NHS) vaccination leaflet, and health care workers, as well as uncertainty-related beliefs, perceived sensitivity of the child to medicines, pessimism, and anxiety were also associated with reporting side effects. Side effect report was associated with lower vaccination intention for the following influenza season. Eighteen percent of children were not re-vaccinated for influenza in 2017/18. Parental report of severe side-effects three days after vaccination (<i>p</i> = .04) and worry about side-effects one month after vaccination (<i>p</i> = .05) were associated with not re-vaccinating.Conclusions: Side effect perception following vaccination is influenced by psychological factors, in particular expectations. Perceiving side effects reduces future vaccination intention. Future public health communications should aim to decrease unrealistic expectations of side effects to increase vaccine uptake.<br>Ethical approval for the study was granted by the NHS Research Ethics Committee (reference: IRAS ID: 192325, REC reference: 16/LO/1003). Following ethical approval, the dataset will be retained until 01/06/2027, then deleted.

背景：导致家长拒绝疫苗接种的主要因素之一，是家长认为疫苗会引发不良反应。尽管疫苗接种后常会出现不适症状，但其诱因往往并非一目了然。部分症状可直接归因于疫苗本身，而其余症状则可能是原本就存在或偶发的身体不适被误归因为疫苗所致。
目的：本研究旨在探讨与儿童流感疫苗接种后家长报告的不良反应、家长次年为孩子再次接种疫苗的意愿，以及实际补种率相关的心理因素。
方法：本研究于2016-2017流感季在伦敦的14家基层医疗诊所开展前瞻性队列研究（ClinicalTrials.gov注册号：NCT02909855）。来自14家诊所的270名家长在孩子接种疫苗前完成了问卷调研。研究分别在接种后3天及接种后1个月开展随访问卷调研，以评估家长报告的不良反应情况及次年疫苗接种意愿，并于2017-2018流感季结束时统计实际补种率。
结果：家长报告的不良反应情况与接种前的不良反应预期密切相关。此外，从媒体、英国国家医疗服务体系（National Health Service, NHS）疫苗接种手册及医护人员处获得的相关信息、与不确定性相关的认知、孩子对药物的敏感性感知、悲观情绪及焦虑状态，同样与不良反应报告行为存在关联。报告不良反应的家长，其次年流感疫苗接种意愿显著更低。2017/2018流感季中，有18%的儿童未再次接种流感疫苗。接种后3天报告严重不良反应（p=0.04）以及接种后1个月对不良反应的担忧（p=0.05）均与未进行流感疫苗补种相关。
结论：疫苗接种后的不良反应感知受心理因素影响，其中尤以预期因素最为显著。对不良反应的感知会降低未来的疫苗接种意愿。未来的公共卫生宣传应致力于降低民众对不良反应的不合理预期，以提升疫苗接种率。
本研究已获得英国国家医疗服务体系研究伦理委员会的伦理批准（编号：IRAS ID: 192325，REC参考编号：16/LO/1003）。经伦理批准后，本数据集将保留至2027年6月1日，随后予以删除。