The Effects of Prenatal Exposure to Seasonal Influenza on Life Course Outcomes in the United States
Seasonal influenza is a common infectious disease that jeopardizes the health of pregnant women. Prenatal exposure to the flu likely disturbs fetal development and harms health at birth, but long run effects have been difficult to identify. I investigate the impact of in utero exposure to seasonal influenza over the life course in the U.S. by exploiting state and time variation in influenza-related mortality, a proxy for disease severity in the local environment. I first show adverse effects on birth weight and an increased risk of heart malformations, and then evaluate impacts on long term outcomes. Exposure to seasonal influenza while in utero increases disability and decreases childhood school attendance, adult high school completion, and labor force participation. I examine implications for influenza vaccination as a policy intervention and find that historical vaccine uptake accounted for economically meaningful improvements in life course outcomes. Furthermore, my estimates suggest substantial returns to future reductions in flu exposure due to vaccination expansions, including 10,000 fewer infants born each year with low birth weight, 54,000 more workers in the labor force, and 34,000 more adults without a disability.