Feasibility of Cocooning Immunization Strategy With Influenza Vaccine (Piiitch)

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.

Intervention Hospital - Standing postpartum vaccine orders, influenza vaccine clinic on postpartum ward for household contacts, mailed vaccine reminders

Intramuscular injection, 0.5 mL or 0.25 mL depending on age of vaccine recipient, one or two doses administered a month apart depending on age and prior influenza vaccination history of recipient

The percent of new mothers delivering at the hospital who reported receiving an influenza vaccine during their pregnancy, in the hospital after delivery, or during the 6 to 8 week postpartum period

The percent of new fathers who as reported by new mothers received an influenza vaccine during the mothers pregnancy, in the hospital after delivery, or during the 6 to 8 week period following the birth of their baby

The percent of all household contacts of newborns who as reported by new mothers received an influenza vaccine during the mothers pregnancy, in the hospital after delivery, or during the 6 to 8 week period following the birth of their baby

Inclusion Criteria: Mother of a newborn delivered at either Durham Regional Hospital or Duke University Hospital between October 2007 and February 2008 Exclusion Criteria: Fetal demise or stillbirth Maternal rights relinquished Language barrier