Quantifying population preferences around vaccination against severe but rare diseases: A conjoint analysis among French university students, 2016

BackgroundSeveral concepts are available to explain vaccine decision making by individual and inter-individual factors, including risk perception, social conformism and altruism. However, only a few studies have quantified the weight of these determinants in vaccine acceptance. Using a conjoint analysis tool, we aimed at eliciting preferences in a student population regarding vaccination against a rare, severe and rapidly evolving hypothetical disease, similar to meningococcal serogroup C meningitis or measles.MethodsDuring March-May 2016, we conducted an emailing survey among university students aged 18–24 years (N = 775) in Rennes, France. Participants were asked to decide for or against immediate vaccination in 24 hypothetical scenarios, containing various levels of four attributes: epidemic situation, adverse events, information on vaccination coverage, and potential for indirect protection. Data were analysed using random effect estimator logit models.ResultsParticipants accepted on average 52% of scenarios and all attributes significantly impacted vaccination acceptance. The highest positive effects were seen with an epidemic situation (OR 3.81, 95%-CI 3.46–4.19), 90% coverage in the community (3.64, 3.15–4.20) and potential for disease elimination from the community (2.87, 2.53–3.26). Information on “insufficient coverage” was dissuasive (vs. none of friends vaccinated: 0.65, 0.56–0.75). Controversy had a significantly greater negative effect than a confirmed risk of severe adverse events (OR 0.05 vs. 0.22). In models including participant characteristics, preference weights were unchanged, while trust in health authorities and vaccination perceptions strongly influenced acceptance themselves. The greatest significant variation of preference weights between subgroups was observed with controversy among students using alternative medicine daily (OR 0.28) and among students relying on scientific vaccine information (OR 0.02).ConclusionsAmong young adults, potential for indirect protection and factual information on coverage in the community and potential side effects positively impact theoretical vaccine acceptance. Conjoint analyses should be conducted to understand vaccine hesitancy in specific vaccination programs.     

Detection of IgG-class antibodies to measles,mumps, rubella,and varicella-zoster virus using a multiplex bead immunoassay

Serologic testing for measles, mumps, rubella, and varicella (MMRV) IgG is traditionally performed by immunofluorescence assay or enzyme immunoassay (EIA). Although sensitive and specific, these methods are labor intensive, time consuming, and require separate assays for each analyte. This study evaluated the performance of the MMRV IgG AtheNA Multi-Lyte® assay using nonclinically characterized serum specimens submitted to our laboratory for routine MMRV IgG testing. Mumps (n = 492) or rubella (n = 500) IgG were initially tested by enzyme-linked fluorescent antibody (ELFA), whereas measles (n = 494) or varicella (n = 497) were analyzed by EIA. Each sample was also tested by the AtheNA Multi-Lyte assay. Discordant results were retested by the predicate method and the multiplex assay, with further discrepancies being arbitrated by a third test. Compared to EIA/ELFA for MMRV IgG, the AtheNA assay demonstrated an overall agreement of 97.4%, 98.2%, 97.6%, and 100%, respectively. Use of this multiplex assay allows for the simultaneous detection of MMRV IgG, potentially decreasing cost, sample volume requirements, aliquot errors, and hands-on testing time.     

Humoral immune response to measles and varicella vaccination in former very low birth weight preterm infants

Introduction

Immune response to vaccination in infants born prematurely may be lower than in infants born at full-term. Some clinical factors might be associated with humoral immune response.

Febrile seizures following measles and varicella vaccines in young children in Australia

BackgroundFebrile seizures (FS) are common in childhood with incidence peaking in the second year of life when measles and varicella-containing vaccines are administered. This study aimed to examine the vaccine-attributable risk of FS following separate administration of MMR and monovalent varicella vaccines (VV) prior to a planned change to MMRV as the second dose of measles-containing vaccine at 18 months of age.MethodsAll FS cases in children aged <5 years from 1st January 2012 to 30th April 2013 were identified from emergency department (ED) and inpatient databases at five Australian tertiary paediatric hospitals participating in PAEDS (Paediatric Active Enhanced Disease Surveillance). Immunization records were obtained from the Australian Childhood Immunization Register (ACIR). The relative incidence (RI) of FS following MMR dose 1 (MMR1) and VV in children aged 11–23 months was determined using the self-controlled case series (SCCS) method and used to calculate attributable risk.ResultsThere were 2013 FS episodes in 1761 children. The peak age at FS was 18 months. The risk of FS was significantly increased 5–12 days post receipt of MMR1 at 12 months (RI = 1.9 [95% CI: 1.3–2.9]), but not after VV at 18 months (RI = 0.6 [95% CI: 0.3–1.2]. The estimated excess annual number of FS post MMR1 was 24 per 100,000 vaccinated children aged 11–23 months (95% CI = 7–49 cases per 100,000) or 1 per 4167 doses.ConclusionsOur study detected the expected increased FS risk post MMR1 vaccine at 12 months, but monovalent varicella vaccine at age 18 months was not associated with increased risk of FS. This provides baseline data to assess the risk of FS post MMRV, introduced in Australia as the second dose of measles-containing vaccine at 18 months of age in July 2013.     

The impact of childhood vaccines on bacterial carriage in the nasopharynx: a longitudinal study

Background

There is increasing evidence that childhood vaccines have effects that extend beyond their target disease. The objective of this study was to assess the effects of routine childhood vaccines on bacterial carriage in the nasopharynx.

Methods

A cohort of children from rural Gambia was recruited at birth and followed up for one year. Nasopharyngeal swabs were taken immediately after birth, every two weeks for the first six months and then every other month. The presence of bacteria in the nasopharynx (Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus) was compared before and after the administration of DTP-Hib-HepB and measles-yellow fever vaccines.

Results

A total of 1,779 nasopharyngeal swabs were collected from 136 children for whom vaccination data were available. The prevalence of bacterial carriage was high: 82.2% S. pneumoniae, 30.6%, S.aureus, 27.8% H. influenzae. Carriage of H. influenzae (OR = 0.36; 95% CI: 0.13, 0.99) and S. pneumoniae (OR = 0.25; 95% CI: 0.07, 0.90) were significantly reduced after measles-yellow fever vaccination; while DTP-Hib-HepB had no effect on bacterial carriage.

Conclusions

Nasopharyngeal bacterial carriage is unaffected by DTP-Hib-HepB vaccination and reduced after measles-yellow fever vaccination.     

麻疹风疹联合减毒活疫苗的稳定性观察

目的  观察麻疹风疹联合减毒活疫苗（麻风二联）的稳定性。方法  将17批北京生物制品研究所有限责任公司（北京公司）2012—2017年生产的麻风二联存放于（5±3）℃,分别在0、9、12、18和24个月按照企业注册标准和中国药典2010或2015年版三部要求进行相关检测。同时对新、旧车间生产的各3批疫苗进行主要质量指标比对。结果  随着存放时间延长,疫苗的病毒滴度呈逐渐下降趋势,麻疹病毒滴度波动于3.9~4.8 lg半数细胞培养感染量（CCID₅₀)/ml,风疹病毒滴度波动于4.0~4.8 lgCCID₅₀/ml,热稳定病毒滴度下降均不超过1.0 lg,疫苗水分不高于3.0%,疫苗的其余各项指标均符合企业注册标准和中国药典要求。新、旧车间生产的疫苗质量没有差别。结论  北京公司生产的麻风二联的质量稳定。     

2012至2013年南通地区麻疹的流行病学分析

目的：探讨南通地区2012～2013麻疹的临床特点、预防接种及治疗转归,为进一步防治麻疹,控制并发症提供依据。方法收集并分析2012～2013年我院传染科麻疹患者的资料并进行回顾性分析。结果近年南通地区麻疹发病率显著升高,年龄分布呈两极分化,婴幼儿（32.6%）及成人（48.8%）所占比率增大。麻疹临床症状典型,黏膜斑较多见;成人麻疹患者全身中毒症状重,多见肝功能损害（57.2%）;婴幼儿麻疹患者支气管炎、支气管肺炎（51.1%）并发症显著高于成人。结论目前麻疹仍以典型性麻疹为主,幼儿发病率较往年明显升高且并发症多见,非典型皮疹病例较往年有所增加。为控制麻疹流行,建议加强麻疹抗体滴度监测及疫苗接种。     

2020-2022年全球消除麻疹面临的挑战

近年来麻疹发病率呈现上升趋势且免疫覆盖率一直停滞不前,难以达到消除麻疹的目标。新型冠状病毒（新冠病毒）大流行后虽然采取的公共卫生措施使同为呼吸道传播的麻疹病例大幅下降,但也导致2020-2021年全球免疫覆盖率进一步下降、疫苗犹豫加剧、监测情况恶化等问题。本文总结各地消除麻疹的最新进展,以及目前需要克服的困难,重点分析了新冠病毒流行对消除麻疹工作的影响,为科学研判麻疹疫情形势和加强新冠病毒流行背景下麻疹的科学防控提供参考。     

Cross sectional survey of Varicella-Zoster virus and measles seropositivity in people living with HIV in a Parisian suburb and a review of current immunization guidelines

According to evidence-based guidelines, vaccines against measles and varicella are generally recommended to susceptible HIV-positive patients, as long as they are not severely immunocompromised. However, routine screening to determine serologic status is not recommended. We conducted a seroprevalence study of anti-measles and anti-Varicella-Zoster virus (VZV) antibodies in adults living with HIV (PLWHA) consulting at Avicenne University Hospital in a Parisian suburb. Sera were collected in years 2018–2020 and tested by commercial immunoassays in 268 patients. Most of the patients were born in Sub-Saharan Africa (55 %) and only 23 % in Europe. Measles and varicella seropositivity were present respectively in 91.4 % and 96.2 % of patients. One patient in ten was seronegative to at least one of tested diseases. In the univariate analysis, only younger age (p = 0.027) was associated with a higher risk of measles seronegativity, while shorter time since arrival in France (p < 0.001) and shorter time since HIV discovery (p = 0.007) were associated with a higher risk of VZV seronegativity. In multivariate analysis no association was found. This study highlights the absence of specific risk factors for VZV and measles seronegativity in PLWHA and supports the importance of routine screening, in order to increase immunization rates and reduce risk of complications.