The term 'Oral Vaccine Developer' can be summarized by the name of Dr. Albert Sabin, a five-letter crossword solution. Dr. Sabin was an American medical researcher and virologist who developed the oral polio vaccine in the 1950s. His vaccine was the first to be administered orally, and it replaced the injectable vaccine developed by Jonas Salk. The Sabin vaccine was widely used around the world and is credited with eradicating polio from most countries.