More than a decade ago, the foundation began an effort to turn a little-known vaccine from China into a world-class tool to fight Japanese encephalitis, an incurable disease also known as "brain fever.” The disease, which is transmitted by mosquitoes, primarily affects children. About 70 percent of people who are infected die or suffer long-term neurological disabilities.

We partnered with the China National Biotec Group and PATH to conduct clinical trials of the vaccine and worked toward its 2013 prequalification by the WHO —the first for a vaccine manufactured in China.

To date, more than 400 million doses of the vaccine have been distributed outside of China. In 2015, Laos launched a nationwide campaign aiming to reach 1.5 million children with the vaccine. It is the first country to introduce the vaccine with the support of Gavi, the global vaccine alliance.

The widespread adoption of the vaccine has been fueled by its low cost, which is a fraction of the cost of other Japanese encephalitis vaccines.