The federal government’s top public health agency has a new director.

Alex Azar, the secretary of Health and Human Services, named long-time infectious disease specialist Robert Redfield as the new director of the Center for Disease Control and Prevention (CDC) on March 21.

The 66-year-old health professional has “dedicated his entire life to promoting public health and providing compassionate care to his patients,” Azar said in a statement. “We are proud to welcome him as director of the world’s premier epidemiological agency.”

Redfield, who did not immediately respond to Fox News' request for comment, will replace Dr. Brenda Fitzgerald, a Trump administration appointee who resigned at the end of January.

Fitzerglad, who headed the CDC for roughly six months, resigned over a conflict of interest. Politico first reported that she had purchased thousands of dollars in shares in a tobacco company shortly after she was named the health agency’s director.

Redfield’s appointment does not require Senate confirmation, meaning he could start the job in a matter of days, according to The Washington Post.

In light of Redfield’s appointment to the CDC, here are 3 things to know about him.

He’s done extensive research on the AIDS virus

While working at the Defense Department's Walter Reed Institute of Research in the 1980s, Redfield began researching the AIDS virus around the height of the epidemic.

At the time, many scientists believed the AIDS virus was only spread among homosexuals. But Redfield questioned this theory, later becoming one of the first researchers to demonstrate heterosexuals could contract the virus as well.

In the 1990s, however, Redfield was accused of misrepresenting data that allegedly bolstered the effectiveness of a new AIDS vaccine. In response, the Army and a Congressional committee investigated his research. Redfield was later cleared of any scientific misconduct.

Around the same time, Redfield also drew criticism from public health leaders for endorsing the isolation of infected soldiers, and for calling for mandatory HIV testing of soldiers and health care workers — even though the CDC and the U.S. surgeon general thought such measures could lead to discrimination and likely wouldn't halt spread of the disease.

He’s worked to combat the opioid epidemic in Maryland

Redfield, who’s a medical school professor at the University of Maryland, co-founded the Institute of Human Virology at the school.

The institute is the first in the U.S. to “combine the disciplines of basic science, epidemiology and clinical research in a concerted effort to speed the discovery of diagnostics and therapeutics for a wide variety of chronic and deadly viral and immune disorders - most notably HIV, the cause of AIDS,” according to its website.

The institute also addresses addiction issues, the Nature Journal reported. Redfield has been praised for his work to fight the opioid crisis.

As the Nature Journal noted, this makes Redfield an “attractive fit” under the Trump administration, which declared the opioid epidemic a public health emergency in October.

He was considered to lead the CDC under President George W. Bush

Redfield, who served from 2005 to 2009 on former President George W. Bush’s presidential advisory council on HIV/AIDS, was also considered by Bush to become the new director of the CDC, The Washington Post reported.

Bush chose Dr. Julie Gerberding instead, who served from 2002 to 2009. She resigned after former President Barack Obama was first elected.

The Associated Press contributed to this report.