scholarly journals Effects of Confounding Bias in COVID-19 and Influenza Vaccine Effectiveness Test-Negative Designs Due to Correlated Influenza and COVID-19 Vaccination Behaviors

2021 ◽  
Author(s):  
Margaret K. K Doll ◽  
Stacy M. Pettigrew ◽  
Julia Ma ◽  
Aman Verma
Keyword(s):  
Influenza Vaccine ◽  
Conditional Probability ◽  
Respiratory Illness ◽  
Vaccine Effectiveness ◽  
The Other ◽  
Acute Respiratory Illness ◽  
Potential Bias ◽  
Confounding Bias ◽  
The Difference ◽  
The Impact

Background: The test-negative design is commonly used to estimate influenza and COVID-19 vaccine effectiveness (VE). In these studies, correlated COVID-19 and influenza vaccine behaviors may introduce a confounding bias where controls are included with the other vaccine-preventable acute respiratory illness (ARI). We quantified the impact of this bias on VE estimates in studies where this bias is not addressed. Methods: We simulated study populations under varying vaccination probabilities, COVID-19 VE, influenza VE, and proportions of controls included with the other vaccine-preventable ARI. Mean bias was calculated as the difference between true and estimated VE. Absolute mean bias in VE estimates was classified as low (<10%), moderate (10% to <20%), and high (≥20%). Results: Where vaccination probabilities are positively correlated, COVID-19 and influenza VE test-negative studies with influenza and SARS-CoV-2 ARI controls, respectively, underestimate VE. For COVID-19 VE studies, mean bias was low for all scenarios where influenza represented ≤50% of controls. For influenza VE studies, mean bias was low for all scenarios where SARS-CoV-2 represented ≤10% of controls. Although bias was driven by the conditional probability of vaccination, low VE of the vaccine of interest and high VE of the confounding vaccine increase its magnitude. Conclusions: Where a low percentage of controls are included with the other vaccine-preventable ARI, bias in COVID-19 and influenza VE estimates is low. However, influenza VE estimates are likely more susceptible to bias. Researchers should consider potential bias and its implications in their respective study settings to make informed methodological decisions in test-negative VE studies.

scholarly journals Impact of Statins on Influenza Vaccine Effectiveness Against Medically Attended Acute Respiratory Illness

2015 ◽  
Vol 213 (8) ◽  
pp. 1216-1223 ◽  
Author(s):  
Saad B. Omer ◽  
Varun K. Phadke ◽  
Robert A. Bednarczyk ◽  
Allison T. Chamberlain ◽  
Jennifer L. Brosseau ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Respiratory Illness ◽  
Vaccine Effectiveness ◽  
Acute Respiratory Illness

scholarly journals Interim estimate of influenza vaccine effectiveness in hospitalised children, Hong Kong, 2017/18

2018 ◽  
Vol 23 (8) ◽  
Author(s):  
Susan S Chiu ◽  
Mike Y W Kwan ◽  
Shuo Feng ◽  
Joshua S C Wong ◽  
Chi-Wai Leung ◽  
...  
Keyword(s):  
Hong Kong ◽  
Confidence Interval ◽  
Influenza Vaccine ◽  
Virus Type ◽  
Interim Analysis ◽  
Respiratory Illness ◽  
Vaccine Effectiveness ◽  
Influenza B ◽  
Acute Respiratory Illness ◽  
Negative Study

We conducted a hospital-based test-negative study in Hong Kong to estimate influenza vaccine effectiveness (VE) for the winter of 2017/18. The interim analysis included data on 1,078 children admitted between 4 December 2017 and 31 January 2018 with febrile acute respiratory illness and tested for influenza. We estimated influenza VE at 66% (95% confidence interval (CI): 43–79) overall, and 65% (95% CI: 40–80) against influenza B, the dominant virus type (predominantly B/Yamagata).

scholarly journals Interim estimates of the effectiveness of seasonal trivalent inactivated influenza vaccine in preventing influenza hospitalisations and primary care visits in Auckland, New Zealand, in 2014

2014 ◽  
Vol 19 (42) ◽  
Author(s):  
N Turner ◽  
N Pierse ◽  
Q S Huang ◽  
S Radke ◽  
A Bissielo ◽  
...  
Keyword(s):  
Primary Care ◽  
New Zealand ◽  
Influenza Vaccine ◽  
Respiratory Illness ◽  
Vaccine Effectiveness ◽  
Acute Respiratory Illness ◽  
Preliminary Results ◽  
Time Of Admission ◽  
Severe Acute Respiratory Illness

We present preliminary results of influenza vaccine effectiveness (VE) in New Zealand using a case test-negative design for 28 April to 31 August 2014. VE adjusted for age and time of admission among all ages against severe acute respiratory illness hospital presentation due to laboratory-confirmed influenza was 54% (95% CI: 19 to 74) and specifically against A(H1N1)pdm09 was 65% (95% CI:33 to 81). For influenza-confirmed primary care visits, VE was 67% (95% CI: 48 to 79) overall and 73% (95% CI: 50 to 85) against A(H1N1)pdm09.

scholarly journals Implementing an Influenza Vaccine Effectiveness Study in a Hospital Context in Portugal: The EVA Hospital Project

2020 ◽  
Vol 33 (13) ◽  
Author(s):  
Ausenda Machado ◽  
Verónica Gomez ◽  
António Panarra ◽  
Jose Poças ◽  
Rita Corte-Real ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Confidence Intervals ◽  
Missing Values ◽  
Disease Onset ◽  
Respiratory Illness ◽  
Vaccine Effectiveness ◽  
Community Dwelling ◽  
Good Precision ◽  
Acute Respiratory Illness ◽  
Severe Acute Respiratory Illness

Introduction: The project ‘Integrated Monitoring of Vaccines in Europe’ aimed to measure seasonal influenza vaccine effectiveness against hospitalised adults, aged 65 years and over, with influenza. We describe the protocol implementation in Portugal.Material and Methods: We implemented a test-negative design, targeting community-dwelling patients aged 65 years old and over hospitalised with severe acute respiratory illness. Patients were reverse transverse-polymerase chain reaction tested for influenza. Cases were those positive for influenza while others were controls. Most variables were collected using hospital medical records. Selection bias was evaluated by comparison with the laboratory influenza test requests database according to demographic characteristics. Crude, season-adjusted influenza vaccine effectiveness was estimated as = 1 – odds ratio, and 95% confidence intervals were obtained by conditional logistical regression, matched with the disease onset month.Results: The recruitment rate was 37.8%. Most participants (n = 368) were female (55.8%) and aged 80 years old and over (55.8%). This was similar to values for potentially eligible severe acute respiratory illness patients (80 years old and over: 56.8%, female: 56.2%). The proportion of missing values was below 2.5% for 20 variables and above 5% (maximum 11.6%) for six variables. Influenza vaccine effectiveness estimates were 62.1% against AH1pdm09 (95% confidence intervals: -28.1 to 88.8), 14.9% against A(H3N2) (95% confidence intervals: -69.6 to 57.3), 43.6% against B/Yam (95% confidence intervals: -66.2 to 80.8).Discussion: Given the non-existence of a coded admission database in either participating hospital the selection of severe acute respiratory illness due to clinical features was the feasible one. These results are only valid for the older adult population residing in the catchment area of the two participating hospitals who were admitted to a public hospital with severe influenza or SARI symptoms.Conclusion: Despite the low participation rate, we observed comparable characteristics of participants and eligible severe acute respiratory illness patients. Data quality was high, and influenza vaccine effectiveness results were in accordance with the results of meta-analyses and European season-specific estimates. The final sample size was low, which inhibited obtaining estimates with good precision.

scholarly journals Investigating the properties of a galaxy group at z = 0.6

2020 ◽  
Vol 15 (S359) ◽  
pp. 188-189
Author(s):  
Daniela Hiromi Okido ◽  
Cristina Furlanetto ◽  
Marina Trevisan ◽  
Mônica Tergolina
Keyword(s):  
Large Scale ◽  
The Other ◽  
Numerical Density ◽  
Spectroscopy Data ◽  
Stellar Kinematics ◽  
Galaxy Groups ◽  
The Galaxy ◽  
The Difference ◽  
The Impact ◽  
The Universe

AbstractGalaxy groups offer an important perspective on how the large-scale structure of the Universe has formed and evolved, being great laboratories to study the impact of the environment on the evolution of galaxies. We aim to investigate the properties of a galaxy group that is gravitationally lensing HELMS18, a submillimeter galaxy at z = 2.39. We obtained multi-object spectroscopy data using Gemini-GMOS to investigate the stellar kinematics of the central galaxies, determine its members and obtain the mass, radius and the numerical density profile of this group. Our final goal is to build a complete description of this galaxy group. In this work we present an analysis of its two central galaxies: one is an active galaxy with z = 0.59852 ± 0.00007, while the other is a passive galaxy with z = 0.6027 ± 0.0002. Furthermore, the difference between the redshifts obtained using emission and absorption lines indicates an outflow of gas with velocity v = 278.0 ± 34.3 km/s relative to the galaxy.

scholarly journals Influenza vaccine effectiveness against hospitalization in the United States, 2019-2020

2020 ◽  
Author(s):  
Mark W Tenforde ◽  
H Keipp Talbot ◽  
Christopher H Trabue ◽  
Manjusha Gaglani ◽  
Tresa M McNeal ◽  
...  
Keyword(s):  
United States ◽  
Influenza Vaccine ◽  
Influenza Vaccination ◽  
Respiratory Illness ◽  
The United States ◽  
Vaccine Effectiveness ◽  
Influenza Viruses ◽  
Current Season ◽  
Hospital Resources ◽  
Negative Controls

Abstract Background Influenza causes significant morbidity and mortality and stresses hospital resources during periods of increased circulation. We evaluated the effectiveness of the 2019-2020 influenza vaccine against influenza-associated hospitalizations in the United States. Methods We included adults hospitalized with acute respiratory illness at 14 hospitals and tested for influenza viruses by reserve transcription polymerase chain reaction. Vaccine effectiveness (VE) was estimated by comparing the odds of current-season influenza vaccination in test-positive influenza cases versus test-negative controls, adjusting for confounders. VE was stratified by age and major circulating influenza types along with A(H1N1)pdm09 genetic subgroups. Results 3116 participants were included, including 18% (553) influenza-positive cases. Median age was 63 years. Sixty-seven percent (2079) received vaccination. Overall adjusted VE against influenza viruses was 41% (95% confidence interval [CI]: 27-52). VE against A(H1N1)pdm09 viruses was 40% (95% CI: 24-53) and 33% against B viruses (95% CI: 0-56). Of the two major A(H1N1)pdm09 subgroups (representing 90% of sequenced H1N1 viruses), VE against one group (5A+187A,189E) was 59% (95% CI: 34-75) whereas no significant VE was observed against the other group (5A+156K) [-1%, 95% CI: -61-37]. Conclusions In a primarily older population, influenza vaccination was associated with a 41% reduction in risk of hospitalized influenza illness.

128 Differences in PRRSV Resilience for Reproductive Performance Between Landrace and Duroc Sows

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 18-19
Author(s):  
Felipe Hickmann ◽  
José Braccini Neto ◽  
Luke M Kramer ◽  
Kent A Gray ◽  
Yijian Huang ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Mixed Model ◽  
Performance Data ◽  
The Other ◽  
Wild Type ◽  
Prrs Virus ◽  
The Difference ◽  
The Impact

Abstract Studies on differences in resilience to porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) between breeds are scarce in the literature. Thus, the objective of this work was to assess PRRSV resilience in PRRSV wild-type infected sows from two breeds. Farrowing data included 2546 and 2522 litters from 894 Duroc and 813 Landrace sows, respectively, which were housed together and experienced the same PRRSV outbreak. Traits used for this study were number of piglets born alive (NBA), number born dead (NBD), total number born (TNB), and number weaned (NW). The impact of PRRSV infection was evaluated by comparing the reproductive performance of breeds between PRRS phases (pre-PRRS, PRRS, and post-PRRS). PRRS phases were defined based on the reproductive performance data. NBA, NBD, and NW were analyzed as a proportion of TNB using a Poisson mixed model. Pre-defined contrasts were used to evaluate the effect of breed on PRRSV resilience and on return to PRRSV-free performance, representing the differences between breeds for the difference between pre-PRRS and PRRS phases, and pre-PRRS and post-PRRS phases, respectively. There was a significant (P ≤ 0.003) interaction between PRRS phase and breed for all traits, as shown in Table 1. In general, reproductive performance reduced from pre-PRRS to PRRS, and then increased from PRRS to post-PRRS, as expected. The resilience contrast was significant for all traits (P ≤ 0.003). In all cases, the drop in percent reproductive performance from pre-PRRS to PRRS was lower for Duroc than for Landrace, indicating that Duroc sows have greater PRRSV resilience than Landrace sows. The return to PRRSV-free performance contrast had a trending effect for NBD (P = 0.055), and it was not significant for the other traits (P ≥ 0.515). These results indicate that Duroc sows have overall greater phenotypic PRRSV resilience for reproductive performance than Landrace sows.

scholarly journals Retraction Note: The impact of repeated vaccination on influenza vaccine effectiveness: a systematic review and meta-analysis

BMC Medicine ◽  
2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Lauren C. Ramsay ◽  
Sarah A. Buchan ◽  
Robert G. Stirling ◽  
Benjamin J. Cowling ◽  
Shou Feng ◽  
...  
Keyword(s):  
Systematic Review ◽  
Influenza Vaccine ◽  
Meta Analysis ◽  
Vaccine Effectiveness ◽  
The Impact

scholarly journals Pragmatic multicentre randomised controlled trial evaluating the impact of a routine molecular point-of-care ‘test-and-treat’ strategy for influenza in adults hospitalised with acute respiratory illness (FluPOC): trial protocol

BMJ Open ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. e031674 ◽  
Author(s):  
Kate Beard ◽  
Nathan Brendish ◽  
Ahalya Malachira ◽  
Samuel Mills ◽  
Cathleen Chan ◽  
...  
Keyword(s):  
Randomised Controlled Trial ◽  
Point Of Care ◽  
Controlled Trial ◽  
Clinical Care ◽  
Respiratory Illness ◽  
Acute Respiratory Illness ◽  
National Guidelines ◽  
South Central ◽  
Randomised Controlled ◽  
The Impact

BackgroundInfluenza infections often remain undiagnosed in patients admitted to hospital due to lack of routine testing. When tested for, the diagnosis and treatment of influenza are often delayed due to the slow turnaround times of centralised laboratory PCR testing. Newer molecular systems, have comparable accuracy to laboratory PCR testing, and can generate a result in under 1 hour, making them potentially deployable as point-of-care tests (POCTs). High-quality evidence for the impact of routine POCT for influenza on clinical outcomes is, however, currently lacking. This large pragmatic multicentre randomised controlled trial aims to address this evidence gap.Methods and analysisThe FluPOC trial is a pragmatic, multicentre, randomised controlled trial evaluating adults admitted to a large teaching hospital and a district general hospital with an acute respiratory illness, during influenza season and defined by Public Health England. Up to 840 patients will be recruited over up to three influenza seasons, and randomised (1:1) to receive either POCT using the FilmArray respiratory panel, or routine clinical care. Clinical and infection control teams will be informed of the results in real time and where influenza is detected clinical teams will be encouraged to offer neuraminidase inhibitor (NAI) treatment in accordance with national guidelines. Those allocated to standard clinical care will have a swab taken for later analysis to allow assessment of missed diagnoses. The outcomes assessment will be by retrospective case note analysis. The outcome measures include the proportion of influenza-positive patients detected and appropriately treated with NAIs, isolation facility use, antibiotic use, length of hospital stay, complications and mortality.Ethics and disseminationPrior to commencing the study, approval was obtained from the South Central Hampshire A Ethics Committee (reference 17/SC/0368, granted 7 September 2017). Results generated from this protocol will be published in peer-reviewed scientific journals and presented at national and international conferences.Trial registration numberISRCTN17197293

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