Influenza Vaccine Protects Both Pregnant Mother and Newborn, According to Cincinnati Children’s Study

Wednesday, October 01, 2008

A new study led by a physician at Cincinnati Children’s Hospital Medical Center shows that influenza vaccine not only prevents pregnant women from getting influenza but also protects their infants.

The study, named Mother’sGift, is the first to demonstrate that the inactivated influenza vaccine provides such dual protection, will be published in the Oct. 9 issue of The New England Journal of Medicine.

“Infants and pregnant women are at increased risk for serious consequences of influenza infection,” says Mark Steinhoff, MD, director of the Division of Global Health at Cincinnati Children’s, who led the study “Inactivated influenza vaccine is recommended for pregnant women in the United States, but is not licensed for infants younger than 6 months of age. Our study demonstrated that inactivated influenza vaccine reduced proven influenza illness by 63 percent in infants up to 6 months and averted approximately a third of all febrile respiratory illnesses in mothers and young infants.”

Dr. Steinhoff conducted the study in his previous capacity as professor in the Bloomberg School’s Department of Public Health, Johns Hopkins University. The study was conducted in Bangladesh in collaboration with researchers from the International Centre for Diarrheal Disease Research there.

Dr. Steinhoff and his colleagues observed 340 mothers and infants from August 2004 through December 2005. Half the mothers received the influenza vaccine, and the others a pneumococcal vaccine. Mothers were interviewed weekly to assess illnesses until 24 weeks after birth. Those who had a fever and respiratory illness received a medical exam, and ill infants were tested for influenza antigens to confirm influenza infection.
Among infants whose mothers had received flu vaccine, there were fewer cases of laboratory-confirmed influenza than among infants in the control group (six cases vs. 16). Respiratory illness with fever occurred in 110 infants whose mothers receive influenza vaccine and 153 infants in the control group. Among mothers who received influenza vaccine, there was a reduction in fever and respiratory illness of 36 percent.

“Infants under six months have the highest rates of hospitalization from influenza among children in the U.S.,” says Dr. Steinhoff. “Data from Dr. Mary Staat’s project at Cincinnati Children’s shows that in some years, up to one in 100 infants below 6 months of age are hospitalized during the flu season. These admission rates are higher than those for the elderly and other high-risk adult groups. Clearly, immunizing pregnant mothers is a strategy with substantial benefits for both mothers and infants. The Mother’s Gift study is an example how data gathered in other regions can be used to protect children in Cincinnati, as well as providing locally relevant information.

The study was funded by the Bill & Melinda Gates Foundation, United States Agency for International Development (USAID), the NPVO Research Fund, Wyeth Pharmaceuticals Inc., the Thrasher Research Fund, Aventis Pasteur, the Johns Hopkins Bloomberg School of Public Health, and the International Centre for Diarrheal Disease Research in Bangladesh.

Cincinnati Children's Hospital Medical Center is one of America’s top three children’s hospitals for general pediatrics and is highly ranked for its expertise in digestive diseases, respiratory diseases, cancer, neonatal care, heart care and neurosurgery, according to the annual ranking of best children's hospitals by U.S. News & World Report. One of the three largest children’s hospitals in the U.S., Cincinnati Children’s is affiliated with the University of Cincinnati College of Medicine and is one of the top two recipients of pediatric research grants from the National Institutes of Health.

For its achievements in transforming healthcare, Cincinnati Children's is one of six U.S. hospitals since 2002 to be awarded the American Hospital Association-McKesson Quest for Quality Prize® for leadership and innovation in quality, safety and commitment to patient care. The hospital is a national and international referral center for complex cases, so that children with the most difficult-to-treat diseases and conditions receive the most advanced care leading to better outcomes.