Flu and pertussis vaccination during pregnancy in Geneva during the COVID-19 pandemic: A multicentric,prospective, survey-based study

ObjectiveTo determine pertussis and influenza vaccination coverage during pregnancy among women delivering in all the maternities of Geneva (Switzerland), during the COVID-19 pandemic.MethodsAll women delivering in all the maternity centres of the canton of Geneva from 1st November 2020 to 30th November 2020 (beginning of the flu vaccination season) and from 8th March 2021 to 7th April 2021 (end of the flu vaccination season) had their records checked upon admission to the labour ward regarding pertussis and influenza vaccination during pregnancy. Reasons for non-vaccination were recorded. Univariate and multivariate analyses were done to identify predictors of vaccine uptake.Results951 women delivered in Geneva during the two study periods, of which 950 were included in the study. 86.2% were vaccinated against pertussis, with no significant difference between the study periods (87.5% vs 85% at the beginning and end of the flu vaccination season respectively). 49.8% were vaccinated against influenza, with no significant difference between the study periods (48.8% vs 50.7% beginning and end of the flu vaccination season respectively). The influenza vaccine was 5 times more likely not to be proposed (8.9% vs. 1.7%) and 3 times more likely to be refused (26.6% vs. 8%) than the pertussis vaccine. Main reason for refusal was a lack of maternal desire for both vaccines, but not vaccine fear. Maternal parity ≥ 1 was significantly associated with pertussis vaccine uptake at univariate analysis. Women were significantly more likely to accept the influenza vaccine if they had a university degree or if they did not deliver in a midwife-only run delivery unit in both univariate and multivariate analysis.ConclusionsIn Geneva, most gynaecologists offer pertussis immunization during antenatal care and uptake is high, but more efforts must be done to increase influenza vaccination coverage. Education level impacts maternal flu vaccination uptake, but other social disparities did not.     

Influenza cases in nine aged care facilities in Sydney,Australia over a three-year surveillance period, 2018—2020

BackgroundInfluenza outbreaks in aged care facilities are a major public health concern. In response to the severe 2017 influenza season in Australia, enhanced influenza vaccines were introduced from 2018 onwards for those over 65 and more emphasis was placed on improving vaccination rates among aged care staff. During the COVID-19 pandemic, these efforts were then further escalated to reduce the additional burden that influenza could pose to facilities.MethodsAn observational epidemiological study was conducted from 2018 to 2020 in nine Sydney (Australia) aged care facilities of the same provider. De-identified vaccination data and physical layout data were collected from participating facility managers from 2018 to 2020. Active surveillance of influenza-like illness was carried out from 2018 to 2020 influenza seasons. Correlation and Poisson regression analyses were carried out to explore the relationship between physical layout variables to occurrence of influenza cases.ResultsInfluenza cases were low in 2018 and 2019, and there were no confirmed influenza cases identified in 2020. Vaccination rates increased among staff by 50.5% and residents by 16.8% over the three-year period of surveillance from 2018 to 2020. For each unit increase in total number of beds, common areas, single rooms, all types of rooms (including double occupancy rooms), the influenza cases increased by 1.02 (95% confidence interval:1.018–1.025), 1.04 (95% confidence interval: 1.019–1.073), 1.03 (95% confidence interval: 1.016–1 0.038) and 1.02 (95% confidence interval:1.005–1.026) times which were found to be statistically significant. For each unit increase in the proportion of shared rooms, influenza cases increased by 1.004 (95% confidence interval:1.0001–1.207) which was found to be statistically significant.ConclusionsThere is a relationship between influenza case counts and aspects of the physical layout such as facility size, and this should be considered in assessing risk of outbreaks in aged care facilities. Increased vaccination rates in staff and COVID-19 prevention and control measures may have eliminated influenza in the studied facilities in 2020.     

Influenza vaccination hesitancy and its determinants among elderly in China: A national cross-sectional study

BackgroundThe Chinese elderly face a significant threat from seasonal influenza, owing to the consistently low vaccination coverage. This study investigated the prevalence and determinants of influenza vaccination hesitancy among the Chinese elderly.MethodsIn 2019, 3849 elderly individuals from 10 provinces in China were recruited in a cross-sectional survey. Multinomial logistic regression was applied to investigate the determinants of influenza vaccination hesitancy.ResultsAmong the elderly respondents, 37.18% expressed some degree of hesitancy towards influenza vaccination: 19.28% were hesitant, and 17.90% refused influenza vaccination, including 19.28% acceptors with doubts and 17.90% refusers. Only 39.10% of the respondents considered themselves as the priority group for influenza vaccination, and 13.93% reported receiving a recommendation for vaccination from healthcare workers. Respondents with higher education levels and from urban areas had significantly higher odds of vaccine hesitancy than their counterparts. Confidence in the safety of vaccines was negatively associated with vaccine hesitancy, but confidence in vaccine efficacy had no such association. Respondents who perceived themselves as highly susceptible to influenza (AOR = 0.85; 95 %CI = 0.77–0.93) and those aware of the elderly as a priority group for influenza vaccination (AOR = 0.51; 95 %CI = 0.41–0.64) had a significantly lower odds of being refusers.ConclusionThis study found a high prevalence of hesitancy towards influenza vaccination among the Chinese elderly, especially well-educated and urban-dwelling respondents. The government should address vaccine hesitancy through culturally appropriate communication, subsidies for vaccination, and actively promoting vaccines through primary care professionals.     

Factors associated with repeated influenza vaccine uptake among aged care staff in an Australian sample from 2017 to 2019

Background/AimInfluenza vaccination is strongly recommended every year for aged care staff to protect themselves and minimise risk of transmission to residents. This study aimed to determine the factors associated with repeated annual influenza vaccine uptake among Australian aged care staff from 2017 to 2019.MethodsDemographic, medical and vaccination data collected from the staff, who participated in an observational study from nine aged care facilities under a single provider in Sydney Australia, were analysed retrospectively. Based on the pattern of repeated influenza vaccination from 2017 to 2019, three groups were identified: (1) unvaccinated all three years; (2) vaccinated occasionally(once or twice) over three years; and (3)vaccinated all three years. Multinomial logistic regression analysis was performed to better understand the factors associated with the pattern of repeated influenza vaccination.ResultsFrom a total of 138 staff, between 2017 and 2019, 28.9 % (n = 40) never had a vaccination, while 44.2 % (n = 61) had vaccination occasionally and 26.8 % (n = 37) had vaccination all three years. In the multinomial logistic regression model, those who were<40 years old (OR = 0.57, 95 % CI: 0.19–0.90, p < 0.05) and those who were current smokers (OR = 0.20; 95 % CI: 0.03–0.76, p < 0.05) were less likely to have repeated vaccination for all three years compared to the unvaccinated group. Those who were<40 years old (OR = 0.61; 95 % CI: 0.22–0.68, p < 0.05) and those who were born overseas (OR = 0.50; 95 % CI:0.27–0.69, p < 0.05) were more likely to be vaccinated occasionally compared to the unvaccinated group.ConclusionThe significant predictors of repeated vaccine uptake across the three-year study period among aged care staff were age, smoking status and country of birth (Other vs Australia). Targeted interventions towards the younger age group (<40 years old), smokers and those who were born overseas could improve repeated influenza vaccination uptake in the aged care workforce.     

Possible correlation between low antigenic drift of A(H1N1) influenza viruses and induction of HI antibodies

This study examined whether, during a seven-year period of low A(H1N1) influenza virus antigenic drift (1988–1989 and 1994–1995, winters), humoral antibody response of elderly volunteers to influenza vaccines could suggest a lack of antibody pressure for drift. In all the years studied A/Taiwan/1/86, the A(HIN1) vaccine component, had a low ability to induce protective hemagglutination-inhibiting (HI) antibody titres ( 1:40). However a similar low immunogenicity was found for some of the different A(H3N2) strain variants of influenza virus, co-circulating in the same period and showing a regular extent of antigenic variations.Although our data could be at least in part explained by the type of study population (elderly and repeatedly vaccinated), postepidemic serological studies did not evidence a consistently lower ability in mounting protective immune response in elderly people as compared with younger against the influenza strains studied. Therefore, our present results did not exclude a true low immunogenicity of A/Taiwan and of some A(H3N2) influenza strains, circulating in the winters examined. This suggests that, besides the necessity to evade prior immunity, additional factors could influence the frequency of influenza viruses antigenic drifts.Abbreviation HI hemagglutination inhibiting     

阔叶十大功劳根中生物碱组分体外抗流感病毒试验研究

利用鸡胚试验技术研究了阔叶十大功劳根中生物碱成分在体外对流感病毒的抑制作用。试验结果表明，阔叶十大功劳根中生物碱成分在20mg／ml时对鸡胚无毒性，0．25mg／ml时仍显示出对甲1型流感病毒较强的抑制作用。     

鼠和兔中流行性感冒病毒抗体的制备及测定

报道了流行性感冒病毒抗体的制备及其抗体价的检测方法。利用鼠、兔对流行性感冒(IFV)抗原的免疫反应制备抗体；酶联免疫法(ELISA)测定抗体价。结果显示：Freund佐剂与抗原的混合乳液，具有流行性感冒病毒的抗原特异性，且能够增强抗原的免疫原性，并改变宿主的免疫反应原性。     

流感DNA疫苗免疫BALB/c小鼠克服母源性抗体干扰的研究

目的 为了克服母源性抗体对子代的免疫抑制作用,寻找避免母源性抗体干扰的流感疫苗免疫策略.方法 以小鼠为动物模型,接种流感灭活疫苗或DNA疫苗,并用致死量流感病毒感染.感染后检测小鼠的存活率、肺部病毒滴度、体内抗体滴度等指标,对疫苗的保护效果进行评价.结果 母代与子代免疫相同的疫苗,不论是灭活疫苗还是DNA疫苗,子代体内的母源性抗体都抑制了子代免疫后的自动免疫应答,表现为子鼠接种疫苗后不能抵御致死量流感病毒感染;母代免疫流感灭活疫苗,子代免疫神经氨酸酶DNA疫苗,子鼠能够克服母源性抗体干扰,抵御致死量流感病毒感染;母代和子代免疫不同的DNA疫苗,即母代免疫血凝素或神经氨酸酶DNA疫苗,子代免疫神经氨酸酶或血凝素DNA疫苗,也能达到克服母源性抗体干扰的目的 .结论 流感DNA疫苗免疫BALB/c小鼠能克服母源性抗体的干扰,这为临床新生儿抗母源性抗体干扰的研究提供了实验参考.     

抗流感病毒抗生素研究开发进展

流感是严重危害人类健康的急性病毒性呼吸道传染病，由于流感病毒抗原变异，常规疫苗尚不能有效预防流感的暴发与流行。因此，抗流感病毒药物研究在流感治疗中具有重要意义。本文就近年来国外抗流感病毒药物研究进展，包括微生物来源的新型抗生素司他弗林(stachyflin)和乙酰司他弗林(acetylstachyflin)，FR198248，FR191512，10-norparvulenone的发现，以及经计算机分子模拟设计的氨基酸类NA抑制剂、环戊烷类NA抑制剂RWJ-270201(BCX-1812)等的开发情况进行概述。     

全球历年人甲型流感病毒H3A1抗原的分子进化研究

目的应用生物信息学数据库和工具，对现有的H3N2亚型人甲型流感病毒全球分离株的H3A1抗原序列进化规律进行分析研究。方法下载NCBI Genbank和流感病毒数据库中全部的甲型流感病毒H3A1序列，首先用两步聚类法进行样本拆分，随后分类绘制出完整的进化树。结果人H3A1序列呈现出单一主干的进化趋势，随着时间的推移，进化树结构和进化模型相关参数均呈现出一定的变化规律，关键变异株的出现则无明显的地域分布特征。结论人流感病毒H3A1抗原的进化主要是病毒抗原漂移和人类免疫选择相互作用的结果，新变异株的出现并未出现明显的地域倾向性，中国华南地区不应当被认为是H3亚型新变异株的发源地。