title: Primary vaccination against smallpox in children under the age of five years--a rural field study.
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D007194:India; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012424:Rural Population; D012899:Smallpox / Q000517:prevention & control*; D014611:Vaccination