5. Olivia Hallisley, 18

hair, face, person, nose, blond,

This brilliant teen is helping make the world healthy again.

She discovered a treatment for Ebola that doesnโ€™t require refrigerationโ€”much more effective for victims of the virus in rural Africa.

Her accomplishments didnโ€™t go unnoticed;

Olivia was recognized in the 2015 Google Science Fair.

Katie Ledecky, 19