Theresa Tam

Dr. Theresa Tam, BMBS, physician, Chief Public Health Officer of Canada (born 1965 in Hong Kong). Dr. Tam is Canada’s chief public health officer, the federal government’s lead public health professional. She has expertise in immunization, infectious diseases and emergency preparedness. She has served on several World Health Organization emergency committees and has been involved in international missions to combat Ebola, MERS (Middle East respiratory syndrome) and pandemic influenza. She has also worked toward the eradication of polio. Dr. Tam became widely known to Canadians through media briefings in 2020 as she led the medical response to the novel coronavirus and the COVID-19 pandemic.

Dr. Theresa Tam, Chief Public Health Officer of Canada at a World Health Assembly event to look at ways to boost public trust in vaccines (29 May 2019).

(courtesy U.S. Mission to International Organizations in Geneva/Wikimedia CC)

Early Career

Dr. Tam was born in Hong Kong and earned her medical degree in the United Kingdom at the University of Nottingham in 1989. She completed a pediatric residency through the University of Alberta in Edmonton in 1996. The following year, she won a fellowship in infectious diseases with the University of British Columbia. She has been a fellow of the Royal College of Physicians and Surgeons of Canada since 1996.

Dr. Tam worked in Ottawa at the Laboratory Centre for Disease Control. She was chief of Health Canada’s immunization and respiratory infections division during the SARS outbreak in 2003.

Chief Public Health Officer

Dr. Tam was named interim Chief Public Health Officer when Dr. Gregory Taylor retired from the position in December 2016. She was named permanently to the position six months later, on 26 June 2017. Dr. Tam is the third physician in the position, which was originally held by Dr. David Butler-Jones.

Her position as chief public health officer is complex. She provides advice to the federal health minister while also heading the Public Health Agency of Canada. The agency was formed in 2004 in the wake of the SARS outbreak to respond to public health threats and emergencies.

After being named to the position, Dr. Tam released a vision statement in which she promised to focus on the needs of the poorest and most marginalized Canadians so they “have a chance to live healthy lives, both physically and mentally.”


As chief public health officer, Dr. Tam is responsible for ensuring Canadians are immunized. She has openly criticized a vocal minority of vaccine refusers, popularly known as anti-vaxxers. “They’re a small number, but they’re spreading misinformation,” Dr. Tam told Chatelaine magazine in 2019. “And they’re communicating their opinions in a very emotional way.”


Dr. Tam became widely known to Canadians through media briefings in 2020 as she led the medical response to the novel coronavirus and the COVID-19 pandemic. She was widely praised for her calm and measured approach. However, Tam was also criticized by some media commentators and Conservative politicians, such as Alberta Premier Jason Kenney, for repeating information from the World Health Organization that was later contested or disproven. This included early claims that there was limited evidence of community transmission. In the midst of the outbreak, Conservative member of Parliament Derek Sloan, a candidate for his party’s national leadership, questioned whether Dr. Tam was working for “China or Canada.” His comments were condemned by others, including some in his own party.