Dr. Rochelle Walensky, who guided the Centers for Disease Control and Prevention through much of the COVID-19 pandemic, is stepping down as the public health agency’s director.

Walensky, 54, has headed the CDC since President Joe Biden was inaugurated in January 2021. 

“Dr. Walensky has saved lives with her steadfast and unwavering focus on the health of every American,” Biden said in a statement. “As Director of the CDC, she led a complex organization on the frontlines of a once-in-a-generation pandemic with honesty and integrity. She marshalled our finest scientists and public health experts to turn the tide on the urgent crises we’ve faced.”

Biden said Walensky is leaving the CDC “a stronger institution, better positioned to confront health threats and protect Americans.”

The CDC said Walensky will depart at the end of June. 

“While at CDC, I had the true gift of meeting, working with, and giving voice to thousands of people at the agency who work 24/7 to worry about health and public health so that the rest of the nation does not have to,” Walensky said in a statement. “I have never been prouder of anything I have done in my professional career.”

Walensky did not say why she is resigning but noted in a letter to Biden that the end of the U.S. COVID-19 public health emergency next week “marks a tremendous transition for our country, for public health, and in my tenure as CDC Director.”

An interim director was not immediately named. Biden must nominate Walensky’s permanent successor. The role does not require Senate confirmation.

Walensky took over the CDC in 2021 amid a winter surge of COVID-19 infections and a bumpy rollout of vaccines under former President Donald Trump. She and other federal health officials worked to make the shots widely available for free, although many Americans resisted the vaccine. 

Walensky also issued recommendations for vaccines for children, booster shots and updated shots. 

But under her watch, the agency drew criticism for sometimes issuing confusing guidance or being slow to change recommendations as conditions changed.

While Walensky’s tenure will be defined largely by the COVID-19 pandemic, the CDC faced other challenges while she was director, including a wave of monkeypox cases and a so-called “tripledemic” of COVID, flu and RSV cases last year.

In August 2022, Walensky announced an overhaul of the CDC’s structure and operation, acknowledging the agency “fell short in many ways” during the coronavirus pandemic and “had some pretty public mistakes.”

The “reset,” as the CDC called it, followed an in-depth review of the agency ordered by Walensky.

Walensky also has been credited with restoring morale at the CDC after accusations that political appointees interfered with pandemic messaging during the Trump administration, frustrating agency scientists.

A CDC review in 2021 found that some guidance was not primarily written by the agency’s staff and that recommendations were sometimes softened when scientific evidence supported stronger wording.