Asked about Sloan’s comments regarding Tam, who was born in Hong Kong, Prime Minister Justin Trudeau said Thursday that “intolerance and racism have no place in our country.”

But the backlash against Tam, whose calm, measured demeanor during daily briefings has earned her legions of fans, raises questions about the prominence of public servants during the Covid-19 pandemic and the risk they run of attracting criticism normally reserved for politicians.

“[Tam] is in this really awkward situation where she’s asked to have a public-facing role, but it was never anticipated that she’d have to defend herself,” said Patrick Fafard, associate professor of public and international affairs at the University of Ottawa.

Unlike most civil servants, public health officers are meant to speak directly to Canadians as credible, objective sources of scientific evidence and health advice, Fafard said. “By and large, it works. But Covid is different because… it’s lasting for a long period of time and [Tam] is in front of the camera every day, and most importantly, the science she’s relying on is now contested,” he said. “She’s become sort of the lightning rod for that.”

Much of the criticism of Tam revolves around information she repeated from the World Health Organization before Covid-19 was widespread in Canada, including that there was limited evidence of community transmission of the virus, and that border closures were not an effective way to limit its spread. She has also been criticized for waiting until early April to suggest that people might want to wear masks in public.

Tam responded briefly to Sloan’s comments on Thursday, only to say that she hadn’t paid them much attention. “My singular focus is to work with all of my colleagues to get this epidemic wave under control,” she said. “I don’t let noise detract me from doing that.”

Giving chief medical officers a platform during a health crisis increases public trust in the government’s response, said Carleton University associate professor Philippe Lagassé, an expert on the Westminster parliamentary system, but it runs the risk of making them appear accountable for policy decisions. Throughout the pandemic, Trudeau and his ministers have said their decisions are being guided by the scientific expertise they receive from Tam.

“It’s always important to make clear that although they’re following scientific advice, they’re the ones making the decisions,” Lagassé said. “Rightly or wrongly, you will expose [public health officers] to attack.”

Sloan isn’t the first politician to question Tam’s judgment as Canada’s top doctor. In an interview last week, Alberta Premier Jason Kenney accused her of “repeating talking points” from China. Far-right media outlet Rebel News has since started a petition calling for her to be fired that has gained more than 33,000 signatures.

But Tam isn’t alone in facing a backlash. In B.C., a Twitter fan page dedicated to provincial health officer Dr. Bonnie Henry that had more than 10,000 followers was deleted on Thursday after the person running it tweeted that it “became a victim of its own success.”

“From death threats and manipulation; this project has been cancelled,” wrote Derek Kleinfeldt, the account’s creator, on Wednesday.

It’s a far cry from the adulation Canada’s top doctors received as the public was just getting to know them. Tam and Henry appeared side by side on a large mural in Vancouver painted several weeks ago. Dr. Horacio Arruda, Quebec’s provincial health director, has inspired countless memes and appeared on a loaf of bread. Alberta’s chief medical officer of health, Dr. Deena Hinshaw, caused a sensation when she appeared in a dress featuring the periodic table.

“I think it comes with the job and with the circumstance and they shouldn’t take it too seriously,” said Sen. Peter Harder, a former senior civil servant. The entire public service is having to work at top speed to roll out the government’s response to the pandemic, he said, and is having to embrace more risk than it’s used to.

Sen. Tony Dean, who was Ontario’s chief public servant during the 2003 SARS outbreak that killed 44 people in Canada, said health crises bring public servants and their expertise to the fore, and called Sloan’s comments about Tam “embarrassing.”

He said public communication and cooperation between governments has been far better during Covid-19 than it was during SARS.

“In a health emergency, there are some communications that can easily be handled by the prime minister and ministers and premiers,” he said. “When it comes to providing a public health perspective… it’s generally better to have an expert or specialist speaking directly to the public, and that’s what we have with Dr. Tam.”