The head of the Biden administration’s global COVID-19 pandemic response is stepping down from her role after eight months, Secretary of State Antony Blinken announced Tuesday.

Gayle Smith will return to her position as leader of the ONE Campaign, an organization focused on ending extreme poverty and preventable disease, with a focus on Africa. Smith’s departure comes as the omicron variant of COVID-19 is spreading, triggering new fears about a surge in cases worldwide.

“As Gayle heads back to the ONE Campaign, she leaves behind a phenomenal set of accomplishments, a robust team and network who are prepared to carry our important work forward, and a comprehensive set of next steps to build on our progress,” Blinken said in a statement. “As Gayle has said many times, our work to defeat this pandemic and prevent future health threats is not over.”

Mary Beth Goodman, a senior member of the State Department’s pandemic response team who previously served as the department’s senior director for global development and humanitarian response, will serve as the acting coordinator in Smith’s absence, Blinken said.

Blinken touted that the U.S. has donated more than 260 million COVID-19 vaccine doses since April. That figure is far shy of the Biden administration’s commitment of 1.2 billion doses, but still puts the U.S. as the top giver of shots to both the global COVAX effort and to individual countries.