The correct choices to fill in the numbered spaces are:
1: polio, 2: vaccines
So the complete passage would read:
The National Foundation for Infantile Paralysis, later renamed the March of Dimes, was established in 1938 and ... was a grassroots campaign run primarily by volunteers. Over the years, millions of people gave small amounts of money to support both the care of people who got polio and research into prevention and treatment. Those contributions financed Jonas Salk, Albert Sabin, and the other researchers who developed the vaccines that children around the world receive today.