ArticleInfection and immunity2000
Constitutive expression of the Vi polysaccharide capsular antigen in attenuated Salmonella enterica serovar typhi oral vaccine strain CVD 909.
Article in Infection and immunity, 2000. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 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.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
23 citing papers in PubMed, 59 citations in OpenAlex.
- Live oral Salmonella enterica serovar Typhi vaccines Ty21a and CVD 909 induce opsonophagocytic functional antibodies in humans that cross-react with S. Paratyphi A and S. Paratyphi B.Clinical and vaccine immunology : CVI · 2014Trial
- Oral priming with Salmonella Typhi vaccine strain CVD 909 followed by parenteral boost with the S. Typhi Vi capsular polysaccharide vaccine induces CD27+IgD-S. Typhi-specific IgA and IgG B memory cells in humans.Clinical immunology (Orlando, Fla.) · 2011Trial
- Genetic engineering ofEcoSal Plus · 2024Review
- Advances in the development of Salmonella-based vaccine strategies for protection against Salmonellosis in humans.Journal of applied microbiology · 2021Review
- Cell mediated immune responses elicited in volunteers following immunization with candidate live oral Salmonella enterica serovar Paratyphi A attenuated vaccine strain CVD 1902.Clinical immunology (Orlando, Fla.) · 2019Article
- Immunogenicity and Induction of Functional Antibodies in Rabbits Immunized with a Trivalent Typhoid-Invasive NontyphoidalMolecules (Basel, Switzerland) · 2018Article
- Manipulation ofFrontiers in immunology · 2018Article
- Live Attenuated Human Salmonella Vaccine Candidates: Tracking the Pathogen in Natural Infection and Stimulation of Host Immunity.EcoSal Plus · 2016Review
- Review
- Adaptation of red blood cell lysis represents a fundamental breakthrough that improves the sensitivity of Salmonella detection in blood.Journal of applied microbiology · 2015Article
- Typhoid fever.Lancet (London, England) · 2015Review
- Serum bactericidal assays to evaluate typhoidal and nontyphoidal Salmonella vaccines.Clinical and vaccine immunology : CVI · 2014Article
- Vaccines against invasive Salmonella disease: current status and future directions.Human vaccines & immunotherapeutics · 2014Review
- Salmonella as a vaccine delivery vehicle.Expert review of vaccines · 2013Review
- Typhoid fever & vaccine development: a partially answered question.The Indian journal of medical research · 2012Review
- Cell-associated flagella enhance the protection conferred by mucosally-administered attenuated Salmonella Paratyphi A vaccines.PLoS neglected tropical diseases · 2011Article
- Salmonella enterica serovar Typhi live vector vaccines finally come of age.Immunology and cell biology · 2009Review
- Regulation of Vi capsular polysaccharide synthesis in Salmonella enterica serotype Typhi.Journal of infection in developing countries · 2008Article
- Generation of specific effector and memory T cells with gut- and secondary lymphoid tissue- homing potential by oral attenuated CVD 909 typhoid vaccine in humans.Mucosal immunology · 2008Article
- Article
Corrections and comments
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Authors and funding
5 authors at 1 institution in 1 country.
Funding
Abstract
Live oral Ty21a and parenteral Vi polysaccharide vaccines provide significant protection against typhoid fever, albeit by distinct immune mechanisms. Vi stimulates serum immunoglobulin G Vi antibodies, whereas Ty21a, which does not express Vi, elicits humoral and cell-mediated immune responses other than Vi antibodies. Protection may be enhanced if serum Vi antibody as well as cell-mediated and humoral responses can be stimulated. Disappointingly, several new attenuated Salmonella enterica serovar Typhi oral vaccines (e.g., CVD 908-htrA and Ty800) that elicit serum O and H antibody and cell-mediated responses following a single dose do not stimulate serum Vi antibody. Vi expression is regulated in response to environmental signals such as osmolarity by controlling the transcription of tviA in the viaB locus. To investigate if Vi antibodies can be stimulated if Vi expression is rendered constitutive, we replaced P(tviA) in serovar Typhi vaccine CVD 908-htrA with the constitutive promoter P(tac), resulting in CVD 909. CVD 909 expresses Vi even under high-osmolarity conditions and is less invasive for Henle 407 cells. In mice immunized with a single intranasal dose, CVD 909 was more immunogenic than CVD 908-htrA in eliciting serum Vi antibodies (geometric mean titer of 160 versus 49, P = 0.0007), whereas O antibody responses were virtually identical (geometric mean titer of 87 versus 80). In mice challenged intraperitoneally with wild-type serovar Typhi 4 weeks after a single intranasal immunization, the mortality of those immunized with CVD 909 (3 of 8) was significantly lower than that of control mice (10 of 10, P = 0.043) or mice given CVD 908-htrA (9 of 10, P = 0.0065).
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Registered trials
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.