title: As it was and as it is: a half-century of progress.
authors.affiliation: Harvard School of Public Health, Massachusetts.
authors.forename: T H
authors.initials: TH
authors.lastname: Weller
mesh_terms: D049673:History, 20th Century; D008404:Massachusetts; D014765:Viral Vaccines / Q000266:history; D014773:Virology / Q000266:history*
chemical_list: D014765:Viral Vaccines