ArticleInfection and immunity1989
Construction and characterization of a Vi-positive variant of the Salmonella typhi live oral vaccine strain Ty21a.
Article in Infection and immunity, 1989. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
7 citing papers in PubMed, 30 citations in OpenAlex.
- Host TGF-β signalling facilitates Vi-capsule mediated adaptive immune evasion and vertical transmission ofCell surface (Amsterdam, Netherlands) · 2025Article
- In vivo tropism of Salmonella Typhi toxin to cells expressing a multiantennal glycan receptor.Nature microbiology · 2018Article
- In vivo regulation of the Vi antigen in Salmonella and induction of immune responses with an in vivo-inducible promoter.Infection and immunity · 2011Article
- Constitutive expression of the Vi polysaccharide capsular antigen in attenuated Salmonella enterica serovar typhi oral vaccine strain CVD 909.Infection and immunity · 2000Article
- Vaccination against typhoid fever: present status.Bulletin of the World Health Organization · 1994Review
- Construction of a recombinant oral vaccine against Salmonella typhi and Salmonella typhimurium.Infection and immunity · 1992Article
- Antigenic role of stress-induced catalase of Salmonella typhimurium in cell-mediated immunity.Infection and immunity · 1992Article
Corrections and comments
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Authors and funding
6 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The viaB locus coding for the Vi antigen of Salmonella typhi Ty2 was cloned on a 40.6-kilobase fragment into the cosmid vector pHC79. The live, oral, attenuated Vi-negative S. typhi Ty21a vaccine strain was transformed with the recombinant cosmid encoding the viaB locus. Homologous recombination of the viaB locus into the chromosome of S. typhi Ty21a was induced by UV irradiation, and Vi-positive recombinants were selected in the presence of D-cycloserine. One such isolate, termed WR4103, contained no plasmids or the attendant antibiotic resistance markers and expressed the Vi antigen stably. Vi antigen extracted from WR4103 was immunologically indistinguishable from Vi antigen purified from S. typhi Ty2. The only detectable difference between Ty21a and WR4103 was in the production of Vi antigen. The mean lethal doses of Ty21a and WR4103 for mice were nearly identical. Immunization of mice with WR4103 engendered a Vi antibody response and afforded complete protection against fatal infection with virulent S. typhi Ty2. Thus, S. typhi WR4103 may serve as an improved oral vaccine for protection against typhoid fever.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.