scholarly journals Seasonal Influenza Vaccine Effectiveness (SIVE): an observational retrospective cohort study – exploitation of a unique community-based national-linked database to determine the effectiveness of the seasonal trivalent influenza vaccine

2013 ◽  
Vol 1 (10) ◽  
pp. 1-46 ◽  
Author(s):  
CR Simpson ◽  
N Lone ◽  
K Kavanagh ◽  
LD Ritchie ◽  
C Robertson ◽  
...  
Keyword(s):  
Primary Care ◽  
At Risk ◽  
Cohort Study ◽  
Influenza Vaccine ◽  
Influenza Vaccination ◽  
Seasonal Influenza ◽  
Rt Pcr ◽  
Risk Patients ◽  
Nationally Representative ◽  
Almost All

BackgroundGlobally, seasonal influenza is responsible for an estimated 3 to 5 million cases of severe illness and 250,000 to 500,000 deaths per year. It is uncertain to what extent national vaccination programmes can prevent this morbidity and mortality.ObjectiveTo determine the effectiveness of the seasonal trivalent inactivated influenza vaccine.DesignWe undertook a retrospective observational cohort study. A propensity score model was constructed and adjusted odds ratios (ORs) were calculated to assess differences in vaccine uptake according to a number of patient characteristics. Adjusted illness and mortality hazard ratios (HRs) were estimated from a Cox proportional hazards model adjusted for sex, age, socioeconomic status, smoking status, urban/rural location, clinical at-risk groups (i.e. patients with chronic respiratory, heart, kidney, liver or neurological disease, immunosuppression and diabetes), Charlson comorbidity index, previous pneumococcal and influenza vaccination, and number of previous primary care consultations, prescribed drugs and hospital admissions. We also included nursing home residence and social care support. Vaccine effectiveness (VE) was expressed as a percentage, and represents a reduction in risk provided by the vaccine for a given outcome (e.g. laboratory-confirmed influenza). This was calculated as 1 − HR, where HR is that of the measured clinical outcome in vaccinated compared with unvaccinated individuals. For estimates of VE derived from linked virological swab data, we carried out a nested case–control study design.SettingA national linkage of patient-level primary care, hospital, death certification and virological swab-linked data across nine influenza seasons (2000–9).ParticipantsA nationally representative sample of the Scottish population during 1,767,919 person-seasons of observation. Cases of influenza were confirmed using reverse transcription-polymerase chain reaction (RT-PCR) in a subset of the population (n = 3323).InterventionsTrivalent inactivated seasonal influenza vaccination (n = 274,071).Main outcome measuresVE, pooled across seasons and adjusting for confounders, was estimated by determining laboratory-confirmed influenza, influenza-related morbidity and mortality including primary care influenza-like illnesses, hospitalisation and death from influenza and pneumonia.ResultsMost vaccines (93.6%;n = 256,474 vaccines) were administered to at-risk patients targeted for vaccination, with a 69.3% uptake among those aged ≥ 65 years (178,754 vaccinations during 258,100 person-seasons). For at-risk patients aged < 65 years there was a 26.2% uptake (77,264 vaccinations during 295,116 person-seasons). VE in preventing RT-PCR laboratory-confirmed influenza was 57.1% [95% confidence interval (CI) 31.3% to 73.3%]. VE was 18.8% (95% CI –103.7% to 67.6%) in patients aged ≥ 65 years and 59.6% (95% CI 21.9% to 79.1%) in those aged < 65 years at risk of serious complications from influenza. In the matched analysis (156,096 person-seasons), adjusted VE for reducing primary care consultations for influenza-like illnesses was 16.3% (95% CI 5.7% to 26.0%). VE in reducing hospitalisations was 19.3% for influenza and pneumonia (95% CI 8.3% to 29.1%) and 26.7% for pneumonia and chronic obstructive pulmonary disease (95% CI 19.8% to 32.9%). VE in reducing death due to influenza and pneumonia was 37.9% (95% CI 29.5% to 45.4%).ConclusionsFew countries' health systems allow for the integrated and accessible data recording that made this study possible and made it feasible to collate centrally almost all hospitalisations and deaths attributed to influenza, thereby allowing completeness of reporting. Using these data, we found most influenza vaccines were administered to those at risk of serious complications from influenza. In a nationally representative cohort we found that the vaccine was associated with a significant decrease in the risk of RT-PCR-confirmed influenza (the decrease was substantial particularly for at-risk patients aged < 65 years) and complications arising from influenza (where more modest decreases were found). Although the modest size of our cohort made it possible to collate centrally almost all cases of influenza-related disease, analysis of subgroups (in particular older age groups) or by individual season resulted in poorer precision and wide CIs. Any future work should therefore aim to address this issue by ensuring adequate power to test VE in these subgroups of patients, while minimising the effect of bias, such as health-seeking behaviour.FundingThe National Institute for Health Research Health Services and Delivery Research programme.

scholarly journals Influenza vaccination during the coronavirus pandemic: intention to vaccinate among the at-risk population in the Central Catalonia Health Region (VAGCOVID)

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Anna Bonet-Esteve ◽  
Raquel Muñoz-Miralles ◽  
Carla Gonzalez-Claramunt ◽  
Ana M Rufas ◽  
Xavier Pelegrin Cruz ◽  
...  
Keyword(s):  
At Risk ◽  
Influenza Vaccine ◽  
Influenza Vaccination ◽  
Vaccination Coverage ◽  
Perceived Risk ◽  
Seasonal Influenza ◽  
Public Health Issue ◽  
Risk Population ◽  
Previous Season ◽  
The Individual

Abstract Background Influenza is a major public health issue, with the primary preventive measure being an annual influenza vaccination. Nevertheless, vaccination coverage among the at-risk population is low. Our understanding of the behaviour of the influenza virus during the SARS-CoV-2 coronavirus pandemic is limited, meaning influenza vaccination is still recommended for individuals at risk for severe complications due to influenza infection. The aim of the study is to determine the intention to vaccinate against seasonal influenza among the at-risk population in the 2020-21 campaign during the SARS-CoV-2 pandemic and to analyse the factors which influence such intention. Methods Cross-sectional telephone survey of adults (aged over 18) with risk factors in central Catalonia where the need for the Seasonal Influenza Vaccine (SIV) was recommended. Results A total of 434 participants responded to the survey, 43.3% of whom intended to be vaccinated against influenza for the 2020-2021 influenza season, 40.8% had no intention to be vaccinated and 15.9% were uncertain or did not express their opinion. The intention to get vaccinated against influenza is associated with having dependents, the individual’s perception of the risk of being infected with influenza and the perceived risk of transmission to dependents. It is also associated with age, whether the individual had received influenza vaccine the previous season or any other season before. The best predictors of the intention to vaccinate are the individual’s perception of the risk of catching influenza and whether the individual had been vaccinated in the previous season. Conclusions Intention to vaccinate can be a good predictor of individual behaviour in relation to vaccination. During the current SARS-CoV-2 pandemic many individuals are hesitant to influenza vaccination. In order to improve influenza vaccination coverage in people included in risk groups, it is necessary to promote educational actions, especially among those who express doubts.

scholarly journals An Audit of Influenza Vaccination Status in Adults with Inflammatory Bowel Disease

2012 ◽  
Vol 26 (9) ◽  
pp. 593-596 ◽  
Author(s):  
Neeraj Narula ◽  
Amit S Dhillon ◽  
Usha Chauhan ◽  
John K Marshall
Keyword(s):  
Primary Care ◽  
Inflammatory Bowel Disease ◽  
Influenza Vaccination ◽  
Bowel Disease ◽  
Seasonal Influenza ◽  
Vaccination Status ◽  
Provider Education ◽  
Seasonal Influenza Vaccination ◽  
Risk Patients ◽  
Inflammatory Bowel

BACKGROUND Several guidelines recommend influenza vaccination for high-risk patients, including those on immune-suppressing medications (IS).OBJECTIVE: To assess the vaccination status and immunization history of an outpatient inflammatory bowel disease (IBD) population for H1N1 and seasonal influenza.RESULTS: Among 250 patients, 104 (41.6%) had been immunized against H1N1 and 62 (24.8%) against seasonal influenza, and 158 (63.2%) were taking IS (azathioprine, 6-mercaptopurine, infliximab, adalimumab, methotrexate, cyclosporine or prednisone). Among subjects on IS, the presence of comorbidities warranting vaccination was associated with higher likelihood of H1N1 immunization (62.5% versus 35.8%; P=0.022) but not of seasonal influenza vaccination (25.0% versus 17.2%; P=0.392). Among patients without comorbidities warranting vaccination, IS was associated with a decreased likelihood of vaccination against seasonal influenza (17.2% versus 30.7%; P=0.036) but not H1N1 (35.8% versus 41.3%; P=0.46). The frequency of H1N1 vaccination was significantly higher among patients who visited a general practitioner at least once yearly (45.7% versus 20%; P=0.0027), with a similar trend for seasonal influenza vaccination (27.1% versus 12.5%; P=0.073). Among 91 patients on IS who declined vaccination, 39.6% reported fear of immediate side effects, 29.7% reported concerns about developing serious medical complications, 15.4% reported concerns about activating IBD and 15.4% were not aware that vaccination was indicated.CONCLUSIONS: Current strategies for vaccinating IBD patients on IS are inadequate. Primary care provider education, incentive programs and regular primary care contact may improve immunization uptake.

scholarly journals Influenza Vaccination Coverage among Registered Nurses in China during 2017–2018: An Internet Panel Survey

Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 134 ◽  
Author(s):  
Jianxing Yu ◽  
Xiang Ren ◽  
Chuchu Ye ◽  
Keqing Tian ◽  
Luzhao Feng ◽  
...  
Keyword(s):  
Primary Care ◽  
Influenza Vaccine ◽  
Influenza Vaccination ◽  
Registered Nurses ◽  
Vaccination Coverage ◽  
Seasonal Influenza ◽  
Panel Survey ◽  
Seasonal Influenza Vaccine ◽  
Factors Influencing ◽  
Principal Factors

Influenza vaccination is recommended for nurses in China but is not mandatory or offered free of charge. The main objective of this study was to determine influenza vaccination coverage and the principal factors influencing influenza vaccination among nurses in China. During 22 March–1 April 2018, we conducted an opt-in internet panel survey among registered nurses in China. Respondents were recruited from an internet-based training platform for nurses. Among 22,888 nurses invited to participate, 4706 responded, and 4153 were valid respondents. Overall, 257 (6%) nurses reported receiving the seasonal influenza vaccine during the 2017/2018 season. Vaccination coverage was highest among nurses working in Beijing (10%, p < 0.001) and nurses working in primary care (12%, p = 0.023). The top three reasons for not being vaccinated were lack of time (28%), not knowing where and when to get vaccinated (14%), and lack of confidence in the vaccine’s effectiveness (12%). Overall, 41% of nurses reported experiencing at least one episode of influenza-like illness (ILI) during the 2017/2018 season; 87% of nurses kept working while sick, and 25% of nurses reported ever recommending influenza vaccination to patients. Compared with nurses who did not receive influenza vaccination in the 2017/2018 season, nurses who received influenza vaccination were more likely to recommend influenza vaccination to patients (67% vs. 22%, p < 0.001). Influenza vaccination coverage among nurses was low, and only a small proportion recommended influenza vaccine to patients. Our findings highlight the need for a multipronged strategy to increase influenza vaccination among nurses in China.

scholarly journals Seasonal Influenza Vaccination During Pregnancy and the Risk of Major Congenital Malformations in Live-born Infants: A 2010–2016 Historical Cohort Study

2020 ◽  
Author(s):  
Maria Peppa ◽  
Sara L Thomas ◽  
Caroline Minassian ◽  
Jemma L Walker ◽  
Helen I McDonald ◽  
...  
Keyword(s):  
Primary Care ◽  
Cohort Study ◽  
Influenza Vaccination ◽  
Congenital Malformations ◽  
Seasonal Influenza ◽  
First Trimester ◽  
Vaccine Uptake ◽  
Historical Cohort ◽  
Historical Cohort Study ◽  
Major Congenital Malformations

Abstract Background Available evidence indicates that seasonal inactivated influenza vaccination during pregnancy protects both the mother and her newborn and is safe. Nevertheless, ongoing safety assessments are important in sustaining vaccine uptake. Few studies have explored safety in relation to major congenital malformations (MCMs), particularly in the first trimester when most organogenesis occurs. Methods Anonymized UK primary care data (the Clinical Practice Research Datalink), including a recently developed Pregnancy Register, were used to identify live-born singletons delivered between 2010 and 2016. Maternal influenza vaccination was determined using primary care records and stratified by trimester. Ascertainment of MCMs from infant primary care records was maximized by linkage to hospitalization data and death certificates. The relationship between vaccination and MCMs recorded in the year after delivery and in early childhood was then assessed using multivariable Cox regression. Results A total of 78 150 live-birth pregnancies were identified: 6872 (8.8%) were vaccinated in the first trimester, 11 678 (14.9%) in the second, and 12 931 (16.5%) in the third. Overall, 5707 live births resulted in an infant with an MCM recorded in the year after delivery and the adjusted hazard ratio when comparing first-trimester vaccination to no vaccination was 1.06 (99% CI, .94–1.19; P = .2). Results were similar for second- and third-trimester vaccination and for analyses considering MCMs recorded beyond the first birthday. Conclusions In this large, population-based historical cohort study there was no evidence to suggest that seasonal influenza vaccine was associated with MCMs when given in the first trimester or subsequently in pregnancy.

scholarly journals Influenza Vaccine Effectiveness in Preventing Severe Outcomes in Patients Hospitalized with Laboratory-Confirmed Influenza during the 2017–2018 Season. A Retrospective Cohort Study in Catalonia (Spain)

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1465
Author(s):  
Lesly Acosta ◽  
Nuria Soldevila ◽  
Nuria Torner ◽  
Ana Martínez ◽  
Xavier Ayneto ◽  
...  
Keyword(s):  
Cohort Study ◽  
Influenza Vaccine ◽  
Influenza Vaccination ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Vaccine Effectiveness ◽  
Public Hospitals ◽  
Categorical Variables ◽  
Type B ◽  
Icu Admission

Seasonal influenza is a common cause of hospital admission, especially in older people and those with comorbidities. The objective of this study was to determine influenza vaccine effectiveness (VE) in preventing intensive care admissions and shortening the length of stay (LOS) in hospitalized laboratory-confirmed influenza cases (HLCI) in Catalonia (Spain). A retrospective cohort study was carried out during the 2017–2018 season in HLCI aged ≥18 years from 14 public hospitals. Differences in means and proportions were assessed using a t-test or a chi-square test as necessary and the differences were quantified using standardized effect measures: Cohen’s d for quantitative and Cohen’s w for categorical variables. Adjusted influenza vaccine effectiveness in preventing severity was estimated by multivariate logistic regression where the adjusted VE = (1 − adjusted odds ratio) · 100%; adjustment was also made using the propensity score. We analyzed 1414 HLCI aged ≥18 years; 465 (33%) were vaccinated, of whom 437 (94%) were aged ≥60 years, 269 (57.8%) were male and 295 (63.4%) were positive for influenza type B. ICU admission was required in 214 (15.1%) cases. There were 141/1118 (12.6%) ICU admissions in patients aged ≥60 years and 73/296 (24.7%) in those aged <60 years (p < 0.001). The mean LOS and ICU LOS did not differ significantly between vaccinated and unvaccinated patients. There were 52/465 (11.2%) ICU admissions in vaccinated cases vs. 162/949 (17.1%) in unvaccinated cases. Patients admitted to the ICU had a longer hospital LOS (mean: 22.4 [SD 20.3] days) than those who were not (mean: 11.1 [SD 14.4] days); p < 0.001. Overall, vaccination was associated with a lower risk of ICU admission. Taking virus types A and B together, the estimated adjusted VE in preventing ICU admission was 31% (95% CI 1–52; p = 0.04). When stratified by viral type, the aVE was 40% for type A (95% CI -11–68; p = 0.09) and 25% for type B (95% CI -18–52; p = 0.21). Annual influenza vaccination may prevent ICU admission in cases of HLCI. A non-significantly shorter mean hospital stay was observed in vaccinated cases. Our results support the need to increase vaccination uptake and public perception of the benefits of influenza vaccination in groups at a higher risk of hospitalization and severe outcomes.

scholarly journals Structural inequities in seasonal influenza vaccination rates

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lara I. Brewer ◽  
Mark J. Ommerborn ◽  
Augustina Le Nguyen ◽  
Cheryl R. Clark
Keyword(s):  
Primary Care ◽  
Health Insurance ◽  
Influenza Vaccine ◽  
Influenza Vaccination ◽  
American Indian ◽  
Low Socioeconomic Status ◽  
Behavioral Risk ◽  
Vaccination Rates ◽  
Access To Primary Care ◽  
Structural Inequities

Abstract Background Influenza immunization is a highly effective method of reducing illness, hospitalization and mortality from this disease. However, influenza vaccination rates in the U.S. remain below public health targets and persistent structural inequities reduce the likelihood that Black, American Indian and Alaska Native, Latina/o, Asian groups, and populations of low socioeconomic status will receive the influenza vaccine. Methods We analyzed correlates of influenza vaccination rates using the 2019 Behavioral Risk Factor Surveillance System (BRFSS) in the year 2020. Our analysis compared influenza vaccination as the outcome of interest with the variables age, sex, race, education, income, geographic location, health insurance status, access to primary care, history of delaying care due to cost, and comorbidities such as: asthma, cardiovascular disease, hypertension, body mass index, cancer and diabetes. Results Non-Hispanic White (46.5%) and Asian (44.1%) participants are more likely to receive the influenza vaccine compared to Non-Hispanic Black (36.7%), Hispanic (33.9%), American Indian/Alaskan Native (36.6%), and Native Hawaiian/Other Pacific Islander (37.9%) participants. We found persistent structural inequities that predict influenza vaccination, within and across racial and ethnic groups, including not having health insurance [OR: 0.51 (0.47–0.55)], not having regular access to primary care [OR: 0.50 (0.48–0.52)], and the need to delay medical care due to cost [OR: 0.75 (0.71–0.79)]. Conclusion As COVID-19 vaccination efforts evolve, it is important for physicians and policymakers to identify the structural impediments to equitable U.S. influenza vaccination so that future vaccination campaigns are not impeded by these barriers to immunization.

Sign in / Sign up

Export Citation Format

Share Document