WASHINGTON (NEXSTAR) — Dr. Anthony Fauci, the nation’s top infectious disease expert, says he plans to step down from his government duties before the end of the year.

While he is stepping down from his government posts, Dr. Fauci said he is not retiring and is moving on to the next phase of his career.

On Monday, Dr. Fauci announced he is stepping down as both adviser to President Joe Biden and as Director of the National Institute of Allergy and Infectious Diseases, a position he held since 1984.

In a statement, Fauci called it the honor of his life to have served as head of that institution.

Dr. Fauci began building his health care legacy when he helped the country through the fight against AIDS in the 1980s. Four decades later, he led efforts to get the country through the Coronavirus pandemic — becoming the face of the COVID-19 response for the Trump administration.

But Fauci fell out of the former president’s favor, as Fauci’s medical advice clashed with Trump’s push to return to normalcy.

Fauci has also advised every U.S. president since Ronald Reagan.

In a statement, President Biden thanked Dr. Fauci for being a dedicated public servant.

Even before Dr. Fauci’s announcement, some speculated Fauci would step down before next year to avoid being drawn into any investigations if Republicans win control of the U.S. House in the midterm elections.

Dr. Fauci denies that has anything to do with his decision.

Meanwhile, Republican Sen. Rand Paul said in a statement that Fauci’s resignation will not prevent a full-throated investigation into the origins of the pandemic. He added that Fauci would be asked to testify about this in reference to the theory that the pandemic may have originated from a Chinese lab leak.

Fauci said he will spend the next few months preparing his department for his departure and that in his next role he hopes to inspire and mentor the next generation of scientific leaders.