Bill Gates got involved with polio via $100 million matching fund to Rotary International about a decade ago. It was one of the foundation’s early healthcare initiatives and leveraged several decades of work by Rotarians around the world...polio eradication was the major project of Rotary at the time.

Malaria is different in that there was not the same level of eradication infrastructure to leverage and different because it touches on drinking water and food chains in the non-human environment. Malaria is not mostly a vaccine distribution problem.