In 1977, Caplan met
Daniel Callahan, a philosopher who co-founded
The Hastings Center (now in
Garrison, New York) with psychiatrist
Willard Gaylin. In 1977, Caplan joined The Hastings Center, first as a junior research assistant and then as a post-doctoral fellow. He spent the next 10 years at the center, serving as the associate director from 1985 to 1987. During this time, Caplan published many papers on genetics (including the ethics of
genetic testing and screening), evolution, sociobiology, and the teaching of ethics. He also became involved in the ethics of human and animal experimentation and new medical technologies, applying philosophy in public discourse and speaking on public policy issues. He worked with William Seidelman, M.D., and others to secure in 2012 an apology from the German Medical Association for the role of German physicians in Nazi prison experiments during the Holocaust. In May 1994, Caplan went to the
University of Pennsylvania in
Philadelphia. He founded the Center for Bioethics and the Department of Medical Ethics and had professorial appointments in a variety of departments including Medicine and Philosophy. While at the University of Pennsylvania, he became the first bioethicist to be sued for his professional role, after his involvement in a gene therapy trial that resulted in the death of research subject
Jesse Gelsinger. The family's suit was settled with the University for an undisclosed amount of money, in exchange for, among other things, dropping Caplan from the suit. The federal government's suit on the same facts was settled for $500,000. In 2009, Caplan helped develop the first flu vaccine mandate at the Children's Hospital of Philadelphia and, later, New York state's policy to require health care workers to "vaccinate or mask". Also in 2009, he called for tightening restrictions on fertility clinics and IVF and has written extensively in favor of embryonic stem cell research. In 2012, Caplan came to
New York University's School of Medicine as the Drs. William F. and Virginia Connolly Mitty Professor of Bioethics and the founding director of the Division of Bioethics. Recent activity has included spearheading a movement to relax restrictions on blood donations by gay men and urging postponement of the Rio Summer Olympics because of the Zika virus threat. In early May 2020, the United States Conference of Mayors announced the Mayors Advisory Panel on Sports, Recreation & Health, with Caplan as a co-chair, to "advise mayors and sports and recreation officials on safe policies and practices as cities reopen from the
COVID-19 pandemic", and in November 2020 he joined the NCAA COVID-19 Medical Advisory Group. MarketWatch featured Caplan in an article on the life of a bioethicist during the COVID-19 pandemic on August 4, 2020. Much of his time from 2020 to present has been focused on the COVID-19 pandemic. He has spoken and written extensively on vaccine-related topics, including the ethics of placebo-controlled trials during the pandemic, what is owed to vaccine trial participants after a vaccine has been authorized,
COVID-19 vaccination of transplant candidates, and more specialized topics such understanding attitudes toward the disease and vaccines among a Haredi-Orthodox Jewish community. He was one of the more vocal proponents of controversial challenge studies for
SARS-CoV2 vaccines. Caplan has been criticized by some classical philosophers for his "hands-on philosophy", This position was criticized by
Lainie Friedman Ross in the
American Journal of Kidney Diseases. In a CNN interview, Caplan said of the unvaccinated: "I'll condemn them. I'll shame them. [...] We can penalize them more. We can say, you're going to pay more on your hospital bill if you aren't vaccinated. You can't get life insurance or disability insurance at affordable rates if you aren't vaccinated." Caplan supported the removal of an unvaccinated patient who was near death from a hospital's transplant waitlist. In 2022, Caplan advocated that pharmaceutical companies should stop doing business in Russia, an action that was criticized as advocating for a war crime. ==Academic work==