[7] Dybul's scientific and clinical research interests have covered the fields of molecular biology, microbiology, virology, pharmacology and especially infectious diseases.

[citation needed] Dybul started his career by working with AIDS patients in San Francisco, California.

[8] On November 15, 2012, he was appointed the next executive director of the Global Fund to Fight AIDS, Tuberculosis and Malaria.

[12] His selection as executive director by the Global Fund's board during its 28th meeting in Geneva was met with praise from both donors and the development community.

World Bank President Jim Yong Kim called Dybul's appointment a "superb choice for a crucial role".

[16] In the preparations for the Global Health Summit hosted by the European Commission and the G20 in May 2021, he was a member of the event's High Level Scientific Panel.