A version of this article appears in print on March 8, 2025, Section A, Page 25 of the New York edition with the headline: James Harrison, Whose Rare Antibodies Helped Millions, Is Dead at 88.

James Harrison, an Australian railway clerk who helped save 2.4 million babies by donating the rare antibodies in his blood every two weeks for more than 60 years, died Feb. 17 at a nursing home ...

Harrison and the baby’s mother, Beth Tibbott, wanted James III to have a sibling, so Henry was born two years later. When James III was a baby, Harrison and Tibbott argued.