Immunology

Biography

Biography: Takahiro Yamada

Abstract

Although, there were no mortalities from the pandemic (H1N1) 2009 among pregnant Japanese women, pregnant women with flu are at higher risk of hospitalization and mortality compared to general population. During the pandemic (H1N1) 2009, it is estimated that more than 60% of pregnant Japanese women were vaccinated against the novel virus. However, as we had no data regarding vaccination coverage rate for seasonal flu in pregnant Japanese women, we conducted a multi-center study to determine vaccination coverage against 2013 – 2014 seasonal flu and the prevalence rate of flu infection among pregnant Japanese women. In that study, 51% of participants reported having received vaccination in or after October 2013. The women aged <25 years had a lower vaccination rate than those aged ≥25 years (P=0.0000). Interestingly, although experience of prior birth did not affect vaccination coverage rate, multiparous women had a higher rate of contracting influenza than primiparous women irresp ective of vaccination status (P=0.0216 and P=0.0003 for women with and without vaccination, respectively). These results raised a question why multiparous pregnant women are more susceptible to flu than primiparous pregnant women. We conducted a study to address this issue during 2014-2015 flu season and results of this study will be presented.