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Brandie Campbell



Barbara A. Cohn, PhD, is director of the Child Health and Development Studies (CHDS) at PHI. CHDS is home to a groundbreaking study, which originated in 1959, designed to shed light on the various factors impacting health during pregnancy and early childhood. Between 1959 and 1967, 15,000 pregnant women and their families were enrolled. Researchers continue to study these rich data and conduct important follow-up studies to further examine how events during pregnancy impact the subsequent health of fathers, mothers and their children and grandchildren. Cohn consults with researchers around the world on the use of the CHDS data for health research.

In addition, Cohn directs research examining how pregnancy protects against breast cancer and influences other health problems in mothers and their children in order to identify natural protective mechanisms that can be used for prevention. She also investigates whether early life exposure to environmental chemicals during pregnancy affects obesity, immune function, reproductive health, cardiovascular disease, diabetes, neurodevelopment, cancer, and health disparities in mothers and their children across the life span.

Cohn holds a doctorate in epidemiology, a master’s degree in city and regional planning, a master’s degree in public health planning and a bachelor’s degree in zoology, all from the University of California, Berkeley.

Recent Highlights

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Breakthrough Infection Study of Over 780,000 Veterans Shows Declining COVID-19 Vaccine Protection

Research from PHI, the Veterans Affairs Medical Center and the University of Texas Health Science Center published in Science found that protection against any COVID-19 infection declined for all vaccine types over six months—with overall protection declining from 87.9% in February to 48.1% by October 2021.  Read the study.

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Barbara Cohn in the LA Times: Dramatic Decline in Effectiveness of all Three COVID-19 Vaccines Over Time

PHI’s Barbara Cohn comments on her groundbreaking research on breakthrough infections, and the significance of the findings for decision-making around the ongoing need for public health measures aimed at countering the spread of COVID-19. See news coverage in the LA Times, Washington Post, the Atlantic and more.

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