Influenza is an important cause of illness and hospitalizations among young infants. However, no influenza vaccine is approved for use in infants less than 6 months of age. Instead, efforts to protect infants have involved immunizations for breastfeeding mothers.

This fall, Cincinnati Children’s will lead a multicenter effort to compare the effectiveness of nasal flu vaccine, which uses a live attenuated virus, versus injected flu vaccine, which uses a killed virus. Enrollment of approximately 240 women will begin in late summer 2011 once influenza vaccines become available. This study is funded by the National Institute of Allergy and Infectious Diseases.

The Centers for Disease Control and Prevention (CDC) recommends that women who are breastfeeding an infant receive an annual influenza vaccine, either via injection or nasal spray. Study participants will be randomized into two groups: one will receive a dose of licensed nasal vaccine and a placebo (saline) injection; the other will receive an injected dose of licensed influenza vaccine and a placebo (inactive sugar water) nasal spray.

Blood samples, nasal swabs, and breast milk samples will be collected from the women, and nasal swabs will be collected from infants for analysis. Mothers and their infants will be followed for approximately 6 months.

For information about vaccine trials, contact the Gamble Program for Clinical Studies at Cincinnati Children’s at or by calling 513-636-7699.