Seropositivity of influenza A H1NI in mothers and infants following maternal vaccination with trivalent seasonal influenza vaccine after the 2009 pandemic

Seroprotection after the 2009 HIN1 pandemic was generally low in pregnant women. Vaccination during pregnancy yielded best seropositivity, whereas receiving a trivalent seasonal influenza vaccine before conception can offer better seroprotection to mothers and newborns than no vaccination.