Reassuring Findings for Mothers Who Have Influenza Vaccine While Pregnant
SAN DIEGO, Calif.
Researchers from the University of California, San Diego School of Medicine and Boston University, in collaboration with the American Academy of Allergy Asthma and Immunology (AAAAI), have found evidence of the H1N1 influenza vaccine’s safety during pregnancy. The national study, which was launched shortly after the H1N1 influenza outbreak of 2009, is summarized in two companion papers published online on September 19 in the journal Vaccine. “The overall results of the study were quite reassuring about the safety of the flu vaccine formulations that contained the pandemic H1N1 strain,” said Christina Chambers, PhD, MPH, Director of the non-profit Organization of Teratology Information Specialists (OTIS) Research Center and lead investigator of UC San Diego’s team. “We believe our study’s results can help women and their doctors become better informed about the benefits and risks of flu vaccination during pregnancy.” Despite federal health authorities’ recommendations that all pregnant women be vaccinated for influenza, it is estimated that less than 50 percent of women follow this advice, largely because they are concerned about the effects flu vaccines might have on the developing baby. Since it was anticipated that the 2009 H1N1 influenza season would be severe, a national study was launched by the Vaccines and Medications in Pregnancy Surveillance System (VAMPSS), a collaboration between UC San Diego School of Medicine and Boston University and coordinated by AAAAI to gather data on the safety of this vaccine during pregnancy. The team from UC San Diego followed 1,032 pregnant women across the United States and Canada who either chose to receive an influenza vaccine or were not vaccinated during one of the three seasons from 2009-2012. Women were recruited through MotherToBaby, a service of OTIS. Chamber’s team found that women vaccinated during pregnancy were no more likely to experience miscarriage, have a baby born with a birth defect or have a baby born smaller than normal compared with those who did not receive a vaccination. Although vaccinated women were more likely to have their babies before term, on average these infants were delivered three days earlier than those born to unvaccinated women.