Maridelis Morales Rosado for TIME

Crises so often tell us who we are and what we’re made of. For Dr. Tedros Adhanom Ghebreyesus, the COVID-19 pandemic is just such a defining moment.

Throughout his career, and as director-general of the World Health Organization, Tedros has stood firmly for equity and access—the idea that all people, wherever they are and whatever their circumstances, have the right to quality health care.

It’s a principle he surely acquired as a child in Ethiopia, where he saw with his own eyes how preventable diseases took the lives of children around him, including his own young brother. It drove him to play a personal role in the response to the Ebola outbreak in the Democratic Republic of Congo. And it shaped him into the face of hope and determination at the center of the COVID-19 storm.

An experienced scientist and public-health leader, Tedros knows that until we protect the most vulnerable among us from COVID-19, none of us is protected.

Okonjo-Iweala is chair of Gavi, the Vaccine Alliance; a WHO and African Union envoy on COVID-19; and former Finance Minister of Nigeria

More Must-Reads from TIME