DEERFIELD, Ill. — Roz Brewer has stepped down as chief executive officer at Walgreens Boots Alliance. She took the job in March 2021, becoming the first African-American and the first woman to lead the chain drug retailer. Brewer also vacated her seat on the WBA board. The company said her sudden departure was mutually agreed upon. Brewer will advise the company while it conducts a search for her successor.

The company said Ginger Graham, a longtime WBA board member, will take over as interim CEO. Graham has extensive experience in the health care sector, including service as CEO of Amylin Pharmaceuticals.

“On behalf of the entire board, I would like to thank Roz for her contributions to WBA,” said executive chairman Stefano Pessina. “Roz navigated the company through the global pandemic, overseeing the critical rollout of vaccines in Walgreens pharmacies and to high-risk populations across the country. She furthered our consumer-facing capabilities while supporting the culture of community and team-member engagement in difficult times. We appreciate her hard work and commitment to the company during this period of unprecedented change.”

Brewer, a former Starbucks and Sam’s Club executive, assumed leadership at Walgreens just as COVID-19 vaccines were becoming available in the United States. She is credited with overseeing a team that successfully built and rolled out the technology for a vaccine scheduling system.

Among other accomplishments, Brewer created a safe operating model for store labor and developed a plan to drive vaccine equity.

To date, Walgreens’ pharmacy personnel have administered more than 70 million COVID vaccine shots.

Brewer and her team also initiated a strategic pivot intended to take the company more deeply into the fast-growing and competitive market for health care services. The blueprint called for shutting down hundreds of underperforming locations and launching reformatted stores, tailored to local communities’ needs.

During her tenure, Walgreens made three strategic acquisitions to enhance its pharmacies as health care destinations. The deals advanced the company’s plans to put physicians on WBA’s payroll and to expand its capabilities in health care services to draw more business from patients covered by Medicare.

Additionally, the  company under Brewer achieved considerable cost savings through its transformational cost-management program.

Walgreens last month warned that it expects earnings for the fiscal year through August to come in at the low end of its forecast, citing softness in consumer spending as well as the ongoing downturn in sales of Covid-related products

“I am grateful to have had the opportunity to lead Walgreens Boots Alliance and to work alongside such talented and dedicated colleagues,” the 61-year-old Brewer said. “I am proud of what we accomplished together. We’ve improved the lives of our employees, expanded health care services for our customers and enhanced our ability to deliver on our purpose of ‘more joyful lives through better health.’

“Over the past several years, we have recruited a world class team to WBA, including the first-ever chief customer officer and the first-ever president of U.S. Healthcare, and invested deeply in the improvement of the company’s overall culture.

“I am confident that WBA is on track to be a leading consumer-centric health care company, serving thousands of communities across the country, especially those that need access to health care the most. I look forward to watching the company continue its transformation to deliver localized health care.”

Pessina said Graham is ideally suited to serve as interim CEO, citing her leadership experience over three decades and across multiple segments of the health care industry, as well as her familiarity with WBA and her strong operational skills.

“Our board and leadership team will intensify our focus on creating value for our customers and our shareholders while we advance the search for a successor with deep health care experience to lead in today’s dynamic environment,” he said.

Graham, 67, has served on the WBA board since 2010. Last year she was named the board’s lead independent director.

Between 2003 and 2007, Graham served as president and CEO of Amylin, a biopharmaceutical company focused on first-in-class medicines for people with diabetes.

Previously, she was group chairman, office of the president, for Guidant Corp., a provider cardiology technology.

Graham also served on the faculty of the Harvard Business School. She started her career at Eli Lilly and Co.

She is a graduate of the University of Arkansas and earned an MBA from Harvard.

“By capitalizing fully on the strength of WBA’s strong mission, values and brand we have an enormous opportunity to play an even more valued role in local health care delivery,” Graham said.