Do Flu Vaccinations for Pregnant Women Protect Infants?

ST. LOUIS – In the wake of the 2009 H1N1 influenza pandemic, the National Institutes of Health has launched a clinical trial that studies the seasonal flu vaccine in pregnant women.

Sharon Frey, M.D.

Saint Louis University, one of the Vaccine and Treatment Evaluation Units (VTEUs) funded by the National Institute of Allergy and Infectious Diseases (NIAID), is among several sites located in various parts of the United States that will recruit pregnant women for the study. Saint Louis University’s Center for Vaccine Development will test the safety and measure the body’s immune response, such as antibody response, to this year’s flu vaccine, as well as examine the vaccine’s ability to protect newborn infants.

“The information from this study will help guide scientists as they work to make vaccines that are more effective in protecting pregnant women and their babies,” said Sharon Frey, M.D., clinical director of Saint Louis University’s Center for Vaccine Development who is leading the research at SLU.

“It is highly recommended that women who are pregnant get vaccinated against influenza because pregnant women can develop very severe illness. Pregnant women who have flu are at high risk of heart and lung complications and have a greater chance of premature labor and delivery.”

Three medical organizations — the Advisory Committee on Immunization Practices (ACIP), American College of Obstetricians and Gynecologists (ACOG) and American Academy of Family Physicians — recommend a flu vaccination for women who are considering pregnancy or likely to have a baby during the flu season.

The study looks at up to 180 pregnant women and up to 60 non-pregnant women from across the country to study whether both groups have a similar antibody response to the vaccine. About 64 of the study volunteers will participate at Saint Louis University.

Researchers also are examining how much antibody pregnant women pass along to their babies to fight flu. Upon delivery of the baby, cord blood will be collected to measure maternal antibodies that are transferred to infants through the placenta.

“Newborns are not protected from flu; they rely on the mother’s antibodies for protection. Our research will tell us whether vaccinating moms also protects young infants. This is important because flu vaccines currently are not approved for babies who are younger than 6 months old,” Frey said.

Women also can choose to participate in a part of the study that looks at how much antibody against the flu virus babies have when they are 6 weeks old.

“It has been shown that babies born with high levels of antibodies in the blood of the umbilical cord are less likely to get flu in the first few months of life,” Frey said. “We hope our research helps us better understand how long this protection may last.”

On the forefront of research in fighting and preventing infectious diseases, Saint Louis University has received federal funding as a Vaccine and Treatment Evaluation Unit for two decades. The Saint Louis University VTEU evaluates new and improved vaccines for diseases such as influenza and novel ways of delivering those vaccines.

Please visit the website for more information on this study.

To learn more about the vaccine research being conducted at Saint Louis University, call (314) 977-6333 or email [email protected]

Nancy Solomon