Effectiveness of seasonal influenza vaccine in preventing medically attended influenza infection in England and Wales during the 2010/2011 season: a primary care-based cohort study.

Background: Estimates of seasonal influenza vaccine effectiveness (VE) are affected by factors such as the strain of the current circulating influenza virus and characteristics of the host.

Objective: The objective of this study was to provide VE estimates for the 2010/2011 seasonal trivalent influenza vaccine (TIV) in preventing medically attended influenza in England and Wales for the season 2010/2011.

Methods: A cohort study design was employed using electronic health records extracted from 104 GP practices in the Royal College of General Practitioners (RCGP) primary care sentinel network.

Effectiveness of trivalent and pandemic influenza vaccines in England and Wales 2008-2010: results from a cohort study in general practice.

Estimation of influenza vaccine effectiveness (VE) is complicated by various degrees of mismatch between circulating and vaccine strains each season. We carried out a cohort study to estimate VE of trivalent (TIV) and pandemic influenza vaccines (PIV) in preventing various respiratory outcomes among general practice (GP) patients in England and Wales between 2008 and 2010. Dates of consultations for influenza-like illness (ILI), acute respiratory tract infection (ARTI), lower respiratory tract infection (LRTI) and nasopharyngeal swabs were obtained from the patient-level electronic records of the 100 practices enrolled in a national GP network.

Recent changes in the prevalence of diseases presenting for health care.

Background: Practice-based morbidity surveys inform on the prevalence of diseases presenting for health care. The last major survey in England and Wales was conducted in 1991.

Aim: To reveal changes in disease prevalence between 1991 and 2001.