Seasonal influenza vaccine effectiveness against influenza in 2012-2013 : A hospital-based case-control study in Lithuania
Background: Due to scarce information on seasonal influenza vaccine effectiveness (SIVE) against severe clinical influenza outcomes in risk populations, we conducted a case-control study to assess its effects against laboratory-confirmed influenza in hospitalized patients during the 2012-2013 influenza season. Methods: We conducted a test-negative case-control study among ≥18 years old patients wi