He inspires trust and confidence in most Americans, but drives others to violent anger – and wild conspiracy theories – over his assertiveness on issues of public health. Anthony Fauci, the United States’ leading expert on infectious diseases and White House coronavirus advisor, is standing firm in the eye of the storm.

For weeks at the beginning of the Covid-19 pandemic, Fauci stood alongside President Donald Trump and the White House coronavirus task force in daily press briefings. Calmly he set the scientific record straight about the Covid-19 situation in the country, even when claims by the Trump administration were called out for being recklessly inaccurate.

Trump abruptly stopped appearing in the public briefings for two months after April 24, and Fauci, painted as alarmist by administration officials, was barred by the White House from making most television appearances.

But he remained in his position as the administration's coronavirus advisor and continued to warn the president and the public of the dangers posed by the virus, which has claimed more than 145,000 lives in the US as of Saturday, according to Johns Hopkins university.

At a sprightly 79, Fauci has been a medical researcher for over five decades. He spent 36 years as the director of the American National Institute of Allergy and Infectious Diseases (NIAID), where he led research through a string of epidemics, including HIV, SARS, Avian flu, Swine flu, Zika and Ebola.

A known workaholic, Fauci, who was the captain of his high school basketball team and an avid marathon runner, stayed fit and beat stress throughout his career by running daily at lunchtime. Now, with the coronavirus crisis filling his days, he has been forced to change that habit and power walk several miles on weekends instead.

“I think the benefit for me is a stress reliever – because I have a pretty high-stress job," Fauci said in a 2016 interview. “Getting outside in the day and hearing the birds and smelling the grass is kind of a very pleasing thing for me.”

Conspiracy theories and threats

His calm insistence on providing the facts, even when they contradict the Trump administration's line, has angered Trump supporters and placed Fauci at the centre of far-right and anti-science conspiracy theories.

On Saturday, the Sinclair Broadcast Group, which owns or operates nearly 200 local TV stations around the United States, announced that it was pulling Sunday’s “America This Week” talk show, which was to feature an interview with an anti-vaccine activist, Judy Mikovits, who says she believes Fauci manufactured the coronavirus and sent it to China.

During the segment, first revealed by Media Matters for America, a banner on the bottom of the screen read “Did Dr. Fauci create coronavirus?"

Before announcing that it would delay the airing of the episode to bring “together other viewpoints and provide additional context”, Sinclair had tweeted that it did not endorse Mikovits’s theory.

Fauci, however, has reacted to criticism with bemused understatement.

When Peter Navarro, a top Trump aide, published an op-ed in USA Today claiming that Fauci was "wrong about everything", Fauci just responded, "You know, it is a bit bizarre. I don't really fully understand it.”

When a security detail was assigned to him after serious threats were made against him and his family he simply described the situation as “not good” and “a little bit disturbing".

“There are people who get really angry at thinking I’m interfering with their life because I’m pushing a public health agenda,” he said Friday in a CNN podcast interview. “The kind of not only hate mail but actual serious threats against me are not good.”

He had come under attack before, over his work with HIV/AIDS. But he said that this time, the threat level was different. “It’s really a magnitude different now because [of] the amount of anger,” he told CNN.

“I’ve seen a side of society that I guess is understandable, but it’s a little bit disturbing,” he said in the interview.

An illustrious career

Fauci has served as adviser to every US president since Ronald Reagan.

A native of Brooklyn, New York, he was born to New York-born parents of Italian origin. After graduating at the top of his class from Cornell University’s medical school, during the Vietnam War, he was called to serve at the National Institutes of Health (NIH), with a group of doctors informally known as the “Yellow Berets”.

He began work there in 1968 as a clinical associate in the Laboratory of Clinical Investigation at the NIAID and served in different roles at the institute before being named its director in 1984.

A pioneer and recognised world leader in the research of HIV/AIDS since the early 1980s, Fauci played a central role in creating the President's Emergency Plan for AIDS Relief, the initiative launched in 2003 by George W. Bush’s administration to address the global epidemic and help save those suffering from the disease.

Following the September 11 attacks on the World Trade center in 2001, he was a driving force in the development of biodefence drugs and vaccines. In 2014, he advised the Obama administration when cases of Ebola were detected in the United States.

‘America’s doctor’

In a New Yorker article titled “How Anthony Fauci Became America’s Doctor”, he is quoted on how, during his many years of advising the White House, he has dealt with leaders in times of crisis. “I go to my favorite book of philosophy, ‘The Godfather,’ and say, ‘It’s nothing personal, it’s strictly business,’” he said.

“You just have a job to do. Even when somebody’s acting ridiculous, you can’t chide them for it. You’ve got to deal with them. Because if you don’t deal with them, then you’re out of the picture.”

When asked about his relationship with Trump, Fauci insists it is very good.

And despite the criticism, Fauci’s handling of the Covid-19 pandemic has also won him huge popularity. A poll released on July 15 by Quinnipiac University showed that 65 percent of voters trust what Fauci says about Covid-19, against 26 percent who do not (compared to Trump, whose information about the coronavirus is not trusted by 67 percent of those polled).

A Change.org petition calling to support Fauci in case Trump considers removing him from the pandemic response team had garnered 332,000 signatures by Sunday, two weeks after it was launched.

If Fauci is concerned about the prospect of being removed, he doesn’t show it.

“I see myself in that role as long as I feel that I’m being useful, and I’m valued in it, and the White House wants me," he told InStyle magazine recently. "If any of the above change, then I would step down.”