Dr. Peter Piot is the recipient of the Canada Gairdner Global Health Award, recognizing his work on the discovery of the Ebola virus in 1976 and his leadership in the global response to the HIV-AIDS epidemic.
Dr. Janet Rossant, chief of research at Toronto's Hospital for Sick Children, is the recipient of the 2015 Canada Gairdner Wightman Award, which honours a Canadian who has demonstrated outstanding leadership in medicine and medical science.
Five international scientists are also being honoured with Canada Gairdner Awards, two each from the United States and Japan and one from Switzerland.
The Gairdners are among the world's most esteemed medical research prizes and each carries a prize of $100,000.
They are awarded annually by the Gairdner Foundation; 82 Gairdner winners have gone on to receive Nobel Prizes.
"The Canada Gairdner Awards distinguish Canada as a leader in biomedical research, raising the profile of science both nationally and on the world stage," Dr. John Dirks, the foundation's president and scientific director, said in a statement announcing the 2015 honourees.
"This year's winners are an exceptional example of the wide implications basic cellular discovery can have on future translational discoveries."
The international winners are:
— Dr. Lewis Cantley, of Weill Cornell Medical College, New York, N.Y., for research that illuminates the pathways that regulate normal cell growth and the defects that cause cell transformation leading to cancer.
— Dr. Michael Hall, of the University of Basel, in Basel, Switzerland, for his discovery of an enzyme that controls cell growth, which is critical to development and aging and widely implicated in cancers, diabetes, cardiovascular and immune diseases.
— Dr. Lynne Maquat of the University of Rochester (N.Y.) School of Medicine and Dentistry for her discovery of nonsense-mediated messenger RNA decay, a quality control mechanism that removes flawed messenger RNA molecules that could trigger disease.
— Dr. Yoshinori Ohsumi of Tokyo Institute of Technology in Tokyo, Japan, for elucidating autophagy, a process in which cells clean up the garbage within themselves.
— Dr. Shimon Sakaguchi of Osaka University in Osaka, Japan, for his discovery of regulatory T cells, which keep the immune system from attacking healthy cells.
The selection committee honoured Rossant for work which has contributed to the understanding of human embryo development and stem cell origins.
Piot, currently the director of the London School of Hygiene and Tropical Medicine, is a former executive director of UNAIDS, the Joint United Nations Program on HIV-AIDS. The award credits his work in identifying the link between tuberculosis and HIV in Africa as well as his role on Ebola.
"Dr. Piot played a leading role in bringing the AIDS epidemic to the forefront of global attention, raising international commitments to its funding and building scientifically grounded responses to its control and treatment," the foundation's statement said.
At the beginning of his career, Piot was a researcher at the Institute of Tropical Medicine in Antwerp, Belgium when the laboratory in which he worked received a sample of blood from a Belgian nun who had died in a mysterious outbreak in Zaire, now the Democratic Republic of the Congo.
The Antwerp lab and another in Britain saw filoviruses in blood from the sample — Ebola is a filovirus — but could not do the tests to determine if this was Marburg virus, an already known filovirus, or a brand new pathogen.
Scientists at the U.S. Centers for Disease Control did that work and confirmed the outbreak was caused by a never before seen virus, which was later named Ebola. The Belgian, British and U.S. teams are all credited with the discovery of the new disease. Later, Piot travelled to Zaire as part of an international team that investigated the first known Ebola outbreak.