Medical 05

Dr. William A. O'Brien III

September 30, 1955 ~ June 3, 2021 (age 65)


Dr. William A. O’Brien III, an accomplished physician-scientist who provided seminal research accomplishments, died on June 3 in Yardley, PA at the age of 65. Dr. O’Brien is survived by his loving wife, sons, sisters, brothers-in-law, and sister-in-law.  He is predeceased by his parents, Dr. William A. O’Brien, Jr. and Rose Mary S. O’Brien, and his brother Timothy O’Brien.

Dr. O’Brien had a distinguished career as researcher and clinician helping patients with serious infections. Dr. O’Brien made several advances in HIV pathogenesis and treatment at University of California in Los Angeles (UCLA) and University of Texas Medical Branch (Galveston, TX), including the first report to demonstrate the need for HIV to use coreceptors to enter cells (O’Brien et al., Nature 1990), the first report showing HIV inhibition of virus entry by blockade of coreceptors (Doranz et al., J Exp Med 1997), and the first report to validate the importance of short-term decreases in the level of HIV in the blood, as the new standard for assessing clinical response to antiviral treatment (O’Brien et al., N Eng J Med 1996). He was an enthusiastic professor and mentor and led research groups in molecular virology as well as in clinical trials for over 20 years. 

He left academic medicine in 2008 to serve as Chief Medical Officer of Zirus, Inc, an antiviral target discovery company in Atlanta (where he met his wife). He moved to Medical Affairs at Boehringer-Ingelheim in 2012, and to Bristol Myers Squibb (BMS) in 2014.  In 2015, he moved to Worldwide Patient Safety for BMS and has served as Safety Management Team (SMT) Chair for products in the Virology, Cardiovascular, and Fibrosis portfolios.

Bill received Bachelor of Science (BS) and Master of Science (MS) degrees in Molecular Biology from the Massachusetts Institute of Technology (MIT; Cambridge, MA). He received his medical degree from the University of Minnesota and completed his post-doctoral training in Internal Medicine and Infectious Diseases at UCLA and the West Los Angeles Veterans Affairs Medical Center.

William Austin O’Brien III was born in Minneapolis, and spent his childhood in nearby Edina, MN, the third of six children of Dr. William A. and Rose Mary (Shevchuk) O’Brien.  He is part of a proud legacy, as his grandfather and father were both accomplished physicians.  William A. O’Brien Sr, MD, was the Dean of the School of Public Health, and started Continuing Medical Education in Minnesota in the 1920s, ahead of nearly all other states, to reflect his belief that physicians should show evidence of ongoing medical education as a requirement for annual licensure.  He also started a doctor call-in radio show in the 1930s on the CBS affiliate in Minneapolis, WCCO, and he became a popular fixture Saturdays at noon.  William A. O’Brien Jr, MD, Bill’s father, was a dedicated public health professor and physician/oncologist with a large general practice of 2000 patients, and he was proud to have a deeply personal relationship with his patients. Like his father, he also broadcast programs on medical health, bringing back the doctor call-in show, and starting a variety of other programs, including Your Health, with Dr. William A. O’Brien every Sunday morning.

 Dr. O’Brien continued the speaker/educator tradition. As an expert in HIV/AIDS molecular virology, Infectious Diseases and HIV/AIDS clinical care, Dr. O’Brien frequently lectured to various audiences on the basic science and management of HIV/AIDS with rapidly evolving therapies, from the time when HIV/AIDS was brand new without any treatments, through a challenging discovery period up to the current state of the art, as HIV/AIDS was ultimately tamed. Now, durable suppression of HIV replication and control of disease is readily achievable. 

Based on Bill’s background in virology and Infectious Diseases, he was selected to be a key contributor to the Bristol Myers Squibb COVID-19 Research & Development Project Management Office for Safety of Study Subjects and Personnel Work Stream. He recently led efforts to develop the BMS COVID-19 Testing, Treatment, and Prevention Guidance for Protocols.

Bill lived life to the fullest with his family and friends and never met a stranger. He will be missed for his enthusiastic and generous personality. Bill’s many passions besides working and making new discoveries, included traveling abroad, playing basketball, running and listening to music. He and his wife were long-standing Symphony season ticket holders in Atlanta and Philadelphia. Bill loved to dine out and try new foods, everyone knew that he would never let anything go to waste. He continued playing basketball throughout his life and even in the distinguished recreational club called the Old Man League in Atlanta.

Bill enjoyed traveling all over the United States and the world. He traveled to every state (except for Alaska) and he traveled to every continent (expect for Antarctica). His beloved destinations included traveling to Thailand for the beautiful cultural; to South Africa on a romantic trip with his wife; and to Kenya on a safari to experience animals in the wild. A few of his favorite cities were Barcelona, Rio de Janeiro, and Sydney.

Bill was actively involved in numerous organizations. He was a member of Phi Gamma Delta Fraternity, whose mission included building courageous leaders, which was the epitome of Bill. As a freshman, Bill was the missing link required to take the house intramural basketball team to win the A-League Championship. He continued to stay connected with his fraternity brothers over the years. He was a member of the MIT Alumni Club of Princeton and met every first Thursday of the month. Bill was a proud member of the family organization called Jack & Jill of America, Bucks County Chapter, and even extended his time during the pandemic to educate teens about the COVID-19 virus and how the vaccine works.

With all that he has accomplished, his greatest loves in life were to spend time with his boys and wife.

Relatives and friends are invited to attend his memorial service on Thursday, July 1, 2021 at 4 PM at the J. Allen Hooper Funeral Chapel, 41 W. Trenton Ave., Morrisville, PA  19067.  His interment will be held privately.

Friends may call on Thursday, July 1, 2021 from 2-4 PM at the funeral chapel.

In lieu of flowers, memorial contributions may be made to the "Dr. William A. O'Brien and Rose Mary O'Brien Scholarship Fund", with checks made payable to University of Minnesota Foundation, P.O. Box 860266, Minneapolis, MN  55486-0266.  (


Gathering of Family and Friends
July 1, 2021

2:00 PM to 4:00 PM
J. Allen Hooper Funeral Chapel
41 W. Trenton Ave.
Morrisville, PA 19067

Celebration of Life
July 1, 2021

4:00 PM
J. Allen Hooper Funeral Chapel
41 W Trenton Ave
Morrisville, PA 19067


Dr. William A. O'Brien and Rose Mary O'Brien Scholarship Fund
University of Minnesota Foundation, P.O. Box 860266, Minneapolis MN 55486-0266

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