OBJECTIVE: To determine the effectiveness of an adjuvanted monovalent vaccine against pandemic influenza A/H1N1 among people with underlying chronic diseases. DESIGN: Historical cohort study. SETTING: Mandatory national reporting systems, 2 November 2009 to 31 January 2010, Denmark. PARTICIPANTS: 388,069 people under 65 years of age with a diagnosis in the past five years of at least one underlying disease expected to increase the risk of severe illness after influenza. MAIN OUTCOME MEASURES: Laboratory confirmed H1N1 infection and influenza related hospital admission with laboratory confirmed H1N1 infection. Estimates of vaccine effectiveness were adjusted for age and underlying disease. RESULTS: The effectiveness of pandemic vaccine against confirmed H1N1 infection 14 days after one dose of vaccine was 49% (95% confidence interval 10% to 71%). The effectiveness of vaccine against admission to hospital for confirmed H1N1 infection was 44% (-19% to 73%). CONCLUSIONS: The adjuvanted monovalent vaccine against pandemic influenza A/H1N1 was offered late in the 2009-10 influenza season. Among chronically ill people, this vaccine offered protection against laboratory confirmed H1N1 infection but only offered non-significant protection against influenza related hospital admissions confirmed as H1N1 infection. This finding is of public health relevance because the population of chronically ill people is a major target group for pandemic vaccinations and because of the delayed availability of pandemic vaccines in a forthcoming pandemic.
OBJECTIVE: To determine the effectiveness of an adjuvanted monovalent vaccine against pandemic influenza A/H1N1 among people with underlying chronic diseases. DESIGN: Historical cohort study. SETTING: Mandatory national reporting systems, 2 November 2009 to 31 January 2010, Denmark. PARTICIPANTS: 388,069 people under 65 years of age with a diagnosis in the past five years of at least one underlying disease expected to increase the risk of severe illness after influenza. MAIN OUTCOME MEASURES: Laboratory confirmed H1N1infection and influenza related hospital admission with laboratory confirmed H1N1infection. Estimates of vaccine effectiveness were adjusted for age and underlying disease. RESULTS: The effectiveness of pandemic vaccine against confirmed H1N1infection 14 days after one dose of vaccine was 49% (95% confidence interval 10% to 71%). The effectiveness of vaccine against admission to hospital for confirmed H1N1infection was 44% (-19% to 73%). CONCLUSIONS: The adjuvanted monovalent vaccine against pandemic influenza A/H1N1 was offered late in the 2009-10 influenza season. Among chronically ill people, this vaccine offered protection against laboratory confirmed H1N1infection but only offered non-significant protection against influenza related hospital admissions confirmed as H1N1infection. This finding is of public health relevance because the population of chronically ill people is a major target group for pandemic vaccinations and because of the delayed availability of pandemic vaccines in a forthcoming pandemic.
Authors: P Vanhems; Y Baghdadi; S Roche; T Bénet; C Regis; B Lina; O Robert; N Voirin; R Ecochard; S Amour Journal: Hum Vaccin Immunother Date: 2016 Impact factor: 3.452
Authors: Won Suk Choi; Ji Yun Noh; Joon Young Song; Hee Jin Cheong; Seong-Heon Wie; Jin Soo Lee; Jacob Lee; Shin-Woo Kim; Hye Won Jeong; Sook-In Jung; Yeon-Sook Kim; Heung Jeong Woo; Kyung Ho Kim; Hun Kim; Woo Joo Kim Journal: Hum Vaccin Immunother Date: 2017-04-13 Impact factor: 3.452
Authors: Salaheddin M Mahmud; Songul Bozat-Emre; Gregory Hammond; Lawrence Elliott; Paul Van Caeseele Journal: PLoS One Date: 2015-11-23 Impact factor: 3.240