Assertion: attenuated vaccine | /r/HasProperty | tested for first time
Facets:
value: on 27 february
type: TEMPORAL
value: on an 8-year-old boy
type: LOCATION
Source sentences:
text: On 27 February 1950, Koprowski's live, attenuated vaccine was tested for the first time on an 8-year-old boy living at Letchworth Village, an institution for the physically and mentally disabled located in New York.