The crash of Swissair Flight 111 at summer’s end robbed us of one of the founding fathers of the global AIDS movement, Dr. Jonathan Mann. He was 51. Celebrated as the architect of the World Health Organization (WHO) Global Program on AIDS, which he built from a staff of two in 1986 into a 250-person, $109 million force by his 1990 resignation, Jonathan blazed trails of awareness and action against the epidemic as it consumed the developing world. He was the first international leader to publicize what he called “the inextricable link between human rights and public health,” fixing high-level attention on such root causes of infection as poverty, illiteracy and the unequal status of women and children. “Had it not been for Jonathan’s unique contributions, the world’s approach to AIDS might very well have gone toward mandatory testing and quarantine,” recalls Dr. Peter Piot, executive director of UNAIDS.

In 1988, Jonathan gathered 100-plus public health officials at WHO’s first World Summit of Health Ministers to adopt the London Declaration of AIDS Prevention, a human-rights approach based on condom promotion rather than draconian measures.

Jonathan’s successes were due to his special gifts: He had the courage and heart of an activist but could speak the language of bureaucracy. In 1990, that integrity drove him to leave his prestigious post in protest against the failure of the United Nations and governments worldwide to respond adequately to the exploding pandemic. In particular, he blasted then WHO director-general Dr. Hiroshi Nakajima for seeking to move WHO’s efforts away from AIDS. AmFAR confounder Dr. Mathilde Krim recalls glowingly, “Jonathan was absolutely fearless—he would talk to heads of state and simply tell them what to do.”

After WHO, Jonathan moved to Harvard’s School of Public Health, where he directed the International AIDS Center and created the François-Xavier Bagnoud Center for Health and Human Rights. In 1992, he cochaired the International AIDS Conference,   which was moved from Harvard to Amsterdam after  he supported activists’ protest of U.S. HIV travel and immigration restrictions.

Before his death, Jonathan had left Harvard to become dean of the School of Public Health at Allegheny University in Philadelphia. He was still as passionate as ever about the epidemic, saying in a speech earlier this year: “Very simply, if 40,000 college students were becoming infected each year, it’s obvious that field trials of a vaccine would have long been underway.”

Also killed in the Swissair crash was Jonathan’s second wife, Mary Lou Clements-Mann, a distinguished researcher in HIV vaccine development with John Hopkins University. She and Jonathan were en route to meetings at UNAIDS headquarters in Geneva when the plane carrying them and 227 other passengers went down.

In my decade as an AIDS activist, I had the good fortune to work with Jonathan many times, from planning the Amsterdam conference to collaborating on the upcoming documentary film A Closer Walk, based on Jonathan’s seminal texts AIDS in the World (Vols. I and II). I was proud to consider him a mentor and a friend.