title: Influenza vaccine effectiveness: best practice and current limitations of the screening method and their implications for the clinic.
abstract: Is there a role for the screening method in estimating influenza vaccine effectiveness (VE)? The answer is yes, but the simplicity of the method used has raised concerns about its validity, and several cautions should be noted. The screening method provides an approximation of influenza VE by comparing the proportion of cases vaccinated (PCV) with the proportion of persons vaccinated (PPV) in the general population. This method has an important disadvantage: VE estimation could be inaccurate if the values for PCV and PPV are drawn from different populations, but it has an important strength, compared with other observational studies, in providing an early indication of VE in the field. Thus, when an infrastructure, such as routine surveillance, is in place to collect robust PCV values, and PPV can be obtained from routine vaccine uptake monitoring systems, the screening method can provide early estimates of influenza VE in target groups.
authors.affiliation: EA7310, Laboratoire de Virologie, Université de Corse-Inserm, Campus Grimaldi, Corte, 20250 France.
authors.forename: Laëtitia
authors.initials: L
authors.lastname: Minodier
authors.forename: Thierry
authors.initials: T
authors.lastname: Blanchon
authors.forename: Cecile
authors.initials: C
authors.lastname: Souty
authors.forename: Clement
authors.initials: C
authors.lastname: Turbelin
authors.forename: Frederic
authors.initials: F
authors.lastname: Leccia
authors.forename: Laurent
authors.initials: L
authors.lastname: Varesi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Falchi
mesh_terms: D004812:Epidemiologic Methods; D006801:Humans; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D017410:Practice Guidelines as Topic; D016896:Treatment Outcome
chemical_list: D007252:Influenza Vaccines
keywords: confounding factor; influenza-like illness; outcome measure; screening method; specificity; surveillance; target group; vaccine coverage; vaccine effectiveness; vaccine efficacy