At the time of his appointment, criticism was rising that the Reagan Administration was not doing enough to respond to AIDS. Although not as prominent in his advocacy for AIDS issues as then-Surgeon General C. Everett Koop, Bowen did offer explicit warnings about the threats posed by the disease, including its risk to heterosexuals. By 1987, he warned that the threat posed by AIDS could rival deadly health disasters like the Black Death, smallpox, and typhoid if more was not done to combat the threat posed by the disease. The following year, after new studies were released showing that the spread of the disease was slowing within many population groups, he commented that "We do not expect any explosion into the heterosexual population."