Google has dedicated a doodle on its homepage to Jonas Salk on scientist's 100th birthday.
Salk, who developed polio vaccine, never patented the vaccine which made him an international hero, the Independent reported.
The illustration depicts two children holding up a sign reading "Thank you, Dr Salk!" paying a tribute to the virologist's work against a disease whose main victims were children.
Salk graduated from New York University School of Medicine in 1939 with his M.D. degree, and soon started work as a staff physician at Mount Sinai Hospital in New York City.
Salk died at age 80 on 23 June, 1995.