Analytic epidemiology about protection against influenza among infants under 6 months of age

Research Project

Project/Area Number	25293152
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Partial Multi-year Fund
Section	一般
Research Field	Hygiene and public health
Research Institution	Osaka City University
Principal Investigator	OHFUJI Satoko 大阪市立大学, 大学院医学研究科, 准教授 (70433290)
Co-Investigator(Kenkyū-buntansha)	FUKUSHIMA Wakaba 大阪市立大学, 大学院医学研究科, 教授 (70420734) KONDO Kyoko 大阪市立大学, 医学部・附属病院運営本部, 技術職員 (80420727) MAEDA Akiko 大阪市立大学, 大学院医学研究科, 研究員 (40250279)
Project Period (FY)	2013-04-01 – 2016-03-31
Project Status	Completed (Fiscal Year 2015)
Budget Amount *help	¥7,540,000 (Direct Cost: ¥5,800,000、Indirect Cost: ¥1,740,000) Fiscal Year 2015: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2014: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000) Fiscal Year 2013: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Keywords	感染症 / インフルエンザ / 乳児 / 疫学 / ワクチン有効性
Outline of Final Research Achievements	To examine the effectiveness of maternal influenza vaccination on preventing influenza in infants under 6 months of age, we conducted a cohort study among 4,068 infants born before 2013/14 influenza season in Osaka. During 2013/14 season, a total of 85 infants (2%) were diagnosed with influenza and 19 infants (0.5%) were hospitalized with influenza. Maternal influenza vaccination (especially prenatal vaccination) revealed to have a decreasing effect on infants' influenza. Vaccine effectiveness of prenatal vaccination was 60% (95% confidence interval: 13%-82%), whereas that of postpartum vaccination was 48% (-41-81%). Although maternal influenza vaccination was also associated with decreasing infants' influenza-related hospitalization, vaccine effectiveness (70%) could not reach to the statistically significance due to limited number of hospitalized cases. Present findings indicated that pregnant women should receive influenza vaccination in order to protect their infants.