Theresa Tam

Early Career

Theresa 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.

Theresa 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

Theresa 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. Tam became the third physician in the position, which was originally held by Dr. David Butler-Jones.

As chief public health officer, Tam provided 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, Tam released a vision statement in which she promised to focus on the needs of the poorest and most marginalized Canadians so that they “have a chance to live healthy lives, both physically and mentally.”

Immunization

As chief public health officer, Theresa Tam was responsible for ensuring that Canadians were immunized. She openly criticized a vocal minority of vaccine refusers, popularly known as anti-vaxxers. “They’re a small number, but they’re spreading misinformation,” Tam told Chatelaine magazine in 2019. “And they’re communicating their opinions in a very emotional way.” (See also Vaccination and Vaccine Hesitancy in Canada.)

COVID-19

Theresa Tam became widely known to Canadians through media briefings as she led the medical response to the novel coronavirus and the COVID-19 pandemic. Tam was 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 general, however, she has been widely praised for her calm and measured approach.

On 20 June 2025, Tam concluded her role and Dr. Howard Njoo was appointed interim chief public health officer. While reflecting on her term, Tam stressed the importance of addressing misinformation related to public health and science.

Honours and Awards

• Honorary Doctor of Science, Simon Fraser University (2021)
• Honorary Doctor of Laws, Carleton University (2024)
• Officer, Order of Canada (2025)
• King Charles III Coronation Medal (2025)