Prevention of Influenza in Infants by Immunization of Their Contacts in the Household

Influenza causes epidemics of respiratory infection in young children each winter. Young children, particularly those under 6 months of age are most vulnerable to suffering from complications secondary to influenza infection. Consequently, influenza vaccine has been recommended for children 6-59 months of age. Influenza vaccine is not approved for use in children under 6 month of age who are at highest risk. Therefore, the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices has recommended vaccination of household contacts of children under 6 month of age - a cocooning strategy.

The current study is a hospital-based study to assess the effectiveness of a program to vaccinate birth mothers and household contacts of newborns with influenza vaccine. We propose to study both birth mothers and household contacts of newborns delivered at Durham Regional Hospital and Duke University Medical Center, birthing hospitals serving Durham and surrounding counties in central North Carolina. We will implement several strategies to increase vaccine coverage rates at Durham Regional Hospital utilizing Duke University Hospital as a comparison setting. Strategies will include: standing vaccine orders for birth mothers, vaccine reminders for household contacts, and a hospital based influenza vaccine clinic to increase vaccine accessibility for household contacts. Vaccine coverage rates will be assessed utilizing a survey method (maternal interview at the birthing hospital and a follow-up telephone contact 6-8 weeks later). We hypothesize that influenza vaccine coverage rates for new mothers and household contacts of newborns delivered at the intervention hospital will be higher when compared to coverage rates in the comparison hospital. Demographic determinants of vaccine coverage and reasons for refusal of influenza vaccine will also be assessed.