Influenza places infants younger than 6 months at risk of poor outcomes. Maternal immunization is known to provide passive protection to the infant through the placenta. The extent of this protection has not been fully explored.
Objectives:
Conduct a prospective infant antibody study to compare 1) infant influenza antibody levels at birth, 2, and 6 months in infants born to women who receive influenza vaccine in early pregnancy, late pregnancy, or do not receive vaccine during pregnancy 2) infant immune response to infant influenza immunization at 6 and 7 months in each vaccine group.
Hypotheses:
Infants born to women who receive influenza vaccine in late pregnancy (>20 weeks gestation) will have 1) higher levels and a longer influenza antibody duration than women who receive vaccine in early pregnancy (≤20 weeks gestation). 2) Fewer infants with pre-existing maternal antibodies will demonstrate protective antibody levels compared to infants without pre-existing antibody levels.
Methods:
150 healthy pregnant women 18-45 years of age seeking care at University of Utah Health Science clinics and their infants are being enrolled. At these visits, we assess participant medical records, collect breast milk and blood from the mother and blood from the infant, and conduct influenza exposure interviews.
Results:
We have currently enrolled and collected data on 11 mother-infant pairs. 6 mothers have delivered infants and one infant has completed the 2 month study visit.
Implications:
Study outcomes will guide future immunization strategies for infants too young to receive primary influenza immunization at 6 and 7 months.