Flu Vaccine Safe and Effective for Pregnant Women, Their Infants

Wednesday, February 01, 2012

Vaccination for influenza is highly successful in reducing sickness among pregnant women and their infants, two groups at high risk for complications from the flu – complications that included 1 percent of all zero to six-month-olds in Hamilton County, Ohio, being hospitalized one year, according to a CDC study.

The protective benefits from flu vaccination – far outweighing the possible bad side effects – are outlined in two recent papers published separately in the American Journal of Obstetrics and Gynecology and the journal Obstetrics and Gynecology.

"Currently, only about 15 percent of pregnant women receive the vaccine," says Mark C. Steinhoff, MD, director of the Center for Global Health at Cincinnati Children’s Hospital Medical Center. "This review should make it crystal clear that pregnant women and their children ages zero to six months are at high risk but can be protected safely and effectively."

Dr. Steinhoff was the corresponding author of the paper in Obstetrics and Gynecology, published in August. He also participated in the review of research and data led by researchers at Johns Hopkins Children’s Center published online by the AJOG on Oct. 22.

A randomized controlled trial by Dr Steinhoff’s group cited in the Obstetrics and Gynecology report showed that immunization reduced flu-like illness by more than 30 percent in both mother and infants and reduced laboratory-proven influenza infections in zero to six-month-old infants by 63 percent.

Dr. Steinhoff reports a “very low rate” of severe adverse events for women who receive the vaccine. The report in AJOG found the same thing and strongly recommends the immunization.

“The lessons learned from flu outbreaks in the distant and not-too-distant past are clear and so are the messages: ‘If you are an expectant mother, get vaccinated. If you are a physician caring for pregnant women, urge your patients to get vaccinated,’ ” said lead investigator Pranita Tamma, MD, an infectious disease specialist at Johns Hopkins.

The researchers looked at three past flu pandemics and 11 published research studies on vaccine safety outcomes over four decades. They found no increased risk of either maternal complications or negative fetal results from flu vaccine.

What they did find is evidence of the dangers flu poses to women: In the first four months of the current H1N1 outbreak this spring, pregnant women were hospitalized at four times the rate of other healthy adults infected with the virus; pregnant women do not get infected more than other adults, but they develop more serious complications and more often; and during the 1957 pandemic, nearly half of all women of childbearing age who died of the flu were pregnant.

Dr. Steinhoff, in the report he authored, calls for a major educational campaign aimed at pregnant women and their caregivers. The message, he said, is that the flu vaccine benefits both the women and their babies.

“The medical community has done a great job of teaching women about prenatal care. Many women are watching carefully what they are putting in their bodies,” Dr. Steinhoff says. “We need them to understand that, 1) they and their young infants are at risk of severe flu and 2) there is both a vaccine and robust evidence that it works.”

About Cincinnati Children’s

Cincinnati Children’s Hospital Medical Center is one of 10 children’s hospitals in the United States to make the Honor Roll in U.S. News and World Reports 2009-10 America’s Best Children’s Hospitals issue. It is #1 ranked for digestive disorders and is also highly ranked for its expertise in respiratory diseases, cancer, neonatal care, heart care, neurosurgery, diabetes, orthopedics, kidney disorders and urology. 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.
President Barack Obama in June 2009 cited Cincinnati Children’s as an “island of excellence” in health care. For its achievements in transforming health care, 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. Additional information can be found at

Contact Information

Tom McCormally, 513-636-9682,