Efficient Transplacental Antibody Transfer From Mother to Fetus Crucial to Infant Health
An international collaboration led by Mark Steinhoff, MD, director of the Division of Global Child Health, is advancing scientific understanding of how to protect infants from respiratory syncytial virus (RSV), the most important viral cause of infant pneumonia, though there is limited data from tropical regions.
The study, published Nov. 15, 2014 in The Journal of Infectious Diseases, is crucial research because, globally, pneumonia is the leading cause of childhood mortality.
The research team, which included colleagues in Seattle, WA, Rochester, NY, and Dhaka, Bangladesh, examined the role of maternal serum antibody in protecting infants from RSV. The team found that efficient transplacental transfer of RSV-specific antibody from mother to the fetus was documented in mother-infant pairs in Asia, and that higher cord-blood antibody titers were associated with infant protection from serologic RSV infection.
Findings were based on serial serum samples collected from mother-infant pairs in Bangladesh, from the third trimester of pregnancy to 72 weeks postpartum. They tested these using an RSV antibody microneutralization assay, and defined serologic infection as a four-fold increase in antibody titer (the highest dilution factor at which a positive reading is yielded). Maternal antibody half-life was calculated using infant antibody titers from birth to 20 weeks.
Researchers found that the ratio of infant cord blood to maternal serum RSV antibody titers in 149 mother-infant pairs was 1.01, and that there was a clear association between higher cord blood RSV antibody titers and lower risk of infant serologic infection.
In addition to this major initiative in battling pneumonia in Bangladesh, Global Child Health also works to assess the disease risks and increase the availability of childhood vaccines for pneumococcal and influenza viruses in other countries with limited resources, including India, Sri Lanka Indonesia and Nepal.