Background: When new vaccine components or platforms are developed, they will typically
need to demonstrate noninferiority or superiority over existing products, resulting in the …

Observational seasonal influenza relative vaccine effectiveness (rVE) studies employ a
variety of statistical methods to account for confounding and biases. To better understand …

Background Relative vaccine effectiveness (rVE) are metrics commonly reported to compare
absolute VE (aVE) of 2 vaccine products. Methods Estimates of rVE for enhanced influenza …

Background Observational studies of influenza vaccine effectiveness (VE) are increasingly
using the test-negative design. Studies are typically based in outpatient or inpatient settings …

Background Study characteristics influence vaccine effectiveness (VE) estimation. We
examined the influence of some of these on seasonal influenza VE estimates from test …

Background Protection provided by seasonal influenza vaccination (SIV) may be measured
against numerous outcomes and their heterogeneity may hamper decision-making. The aim …

Background Evidence on influenza vaccine effectiveness (VE) is commonly derived from
observational studies. However, these studies are prone to confounding by indication and …

Evaluation of influenza vaccine effectiveness Page 1 Evaluation of influenza vaccine effectiveness A
guide to the design and interpretation of observational studies Immunization, Vaccines and …

Systematic reviews and meta‐analyses confirm that influenza vaccination reduces the risk of
influenza illness by between about 40% and 60% in seasons when circulating influenza …

Background: Estimating influenza vaccine effectiveness using an unvaccinated comparison
group may result in biased effect estimates. Objectives: To explore the reduction of …