a1 Bavarian Health and Food Safety Authority, Oberschleißheim, Germany
a2 The European Programme for Intervention Epidemiology Training (EPIET), ECDC, Stockholm, Sweden
We estimated the vaccine effectiveness (VE) of trivalent and monovalent influenza vaccines, respectively, against laboratory-confirmed influenza infections in patients with influenza-like illness who visited physicians participating in the Bayern Influenza Sentinel in Bavaria, Germany during 2010/2011. Swab specimens were analysed for influenza A(H1N1)pdm09, A(H3) and B by PCR. VE was estimated using the test-negative case-control study design and logistic regression. In total, 1866 patients (790 cases, 1076 controls) were included. The VE of trivalent vaccines administered in season 2010/2011 against laboratory-confirmed infection with any influenza virus, adjusted for age group, sex, chronic illness and week of arrival of the specimen, was 67·8% [95% confidence interval (CI) 39·2–82·9)]. The adjusted VE of monovalent influenza vaccines administered in season 2009/2010 against laboratory-confirmed influenza A(H1N1)pdm09 infection in 2010/2011 was 38·6% (95% CI −70·0 to 77·8). This is the first VE study conducted in Bavaria. We concluded that the trivalent influenza vaccines were effective in our study population.
(Received June 14 2012)
(Revised August 14 2012)
(Accepted September 19 2012)