Dr. Summer Sitima, born into a Kenyan family with 24 siblings during the 1990s—a period marked by the HIV epidemic in Sub-Saharan Africa—has a vivid memory from 1997 that deeply impacted her life. As a child, she witnessed the arrival of her sister's husband at their door, carrying the frail body of her older sister, who was suffering from advanced HIV. Her sister had contracted the virus as a teenager through marriage and received no treatment. For six weeks, Summer and her family cared for her sister until she passed away.
Reflecting on that experience, Summer says, "It changed my life forever. From that moment, I developed a keen interest in healthcare and its impact on people's lives." Determined to break barriers, she became the first of her family's 13 daughters to graduate from high school, and she later achieved another milestone by earning a college degree. Summer also defied expectations by staying unmarried during her teenage years and pursuing a career in medicine.
Today, Summer serves as Gilead’s Commercial Operations Lead in South Africa, a country where half of all new HIV cases are diagnosed in adolescents. According to the World Health Organization (WHO), 25.6 million people in Africa are living with HIV, and 91 million are affected by hepatitis B or C. Summer credits her team’s dedication and resilience in overcoming societal and structural challenges to reach those most in need of healthcare in the region.
Summer points out that policies in the 1990s, driven by fear and misinformation, have left many young people born after 2000 with inadequate knowledge about HIV transmission and access to care. Gilead collaborates with various partners to provide testing, treatment, and education to combat stigma. In Nairobi, for example, an initiative trains barbers and hairdressers to serve as HIV educators. "Barbershops and salons are spaces where people naturally engage in conversations and trust those they speak with," says Summer.
Gilead also supports a charity run in Nairobi, with proceeds aiding medical students at the University of Nairobi. These students learn about sexually transmitted infections (STIs) through engaging activities like game nights and social media campaigns, which help spread awareness among their peers and the broader community. "This creates a ripple effect, educating more people and ultimately benefiting the community," Summer explains.
Another innovative project involves tree planting, which improves access to healthcare during extreme weather conditions by aiding water drainage and enhancing the ecosystem. Summer notes that such initiatives help ensure that girls, who are at high risk of dropping out of school and becoming pregnant during these periods, can continue their education.
Over 25 years after her sister's death, Summer acknowledges that women like her sister now have better access to information and healthcare, thanks in part to the efforts of organizations like Gilead.
“I’m motivated every day to create new possibilities for women, like my sister,” explains Summer. “We are changing the stories of mothers, daughters, sisters, wives and young people in Africa, and around the world.”