title: Salmonella typhi Vi antigen-negative isolates in India and prophylactic typhoid immunization.
authors.forename: S C
authors.initials: SC
authors.lastname: Arya
mesh_terms: D006801:Humans; D012485:Salmonella typhi / Q000235:genetics* / Q000302:isolation & purification; D014435:Typhoid Fever / Q000382:microbiology / Q000517:prevention & control*; D014436:Typhoid-Paratyphoid Vaccines / Q000276:immunology*
chemical_list: D014436:Typhoid-Paratyphoid Vaccines