Trial reportThe Journal of infectious diseases2026
Safety and Immunogenicity of a Klebsiella pneumoniae Tetravalent Bioconjugate Vaccine (Kleb4V) Administered to Healthy Adults: A First-in-Human Phase I/II Randomized and Controlled Study.
Trial report in The Journal of infectious diseases, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04959344 (Safety and Immunogenicity of a Klebsiella Pneumoniae Tetravalent Bioconjugate Vaccine), which is not on this map. Cited by 16 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.
Safety and Immunogenicity of a Klebsiella Pneumoniae Tetravalent Bioconjugate Vaccine (Kleb4V) Administered to Healthy Adults: A FTIH Phase I/II Randomized and Controlled Study
Who cites it
16 citing papers in PubMed.
- ElevatedEmerging microbes & infections · 2026Article
- Article
- Antimicrobial resistance and plasmidome of carbapenemase-resistant Klebsiella pneumoniae causing bloodstream infections between 2014 and 2024.BMC microbiology · 2026Article
- Understanding the impact of Klebsiella pneumoniae K-Antigen based MAPS vaccine design on the immune response in animal models.PLoS pathogens · 2026Article
- Article
- Modular Development of aNanomaterials (Basel, Switzerland) · 2026Article
- Development of an 8-valentFrontiers in immunology · 2026Article
- Klebsiella vaccine research and development in Africa: a rapid scoping review of current evidence and future priorities.BMJ public health · 2026Article
- NovelmBio · 2025Article
- Antimicrobial resistance and vaccines in Enterobacteriaceae including extraintestinal pathogenic Escherichia coli and Klebsiella pneumoniae.npj antimicrobials and resistance · 2025Review
- Vaccines and monoclonal antibodies to prevent healthcare-associated bacterial infections.Clinical microbiology reviews · 2024Review
- Investigation into the efficiency of diverse N-linking oligosaccharyltransferases for glycoengineering using a standardised cell-free assay.Microbial biotechnology · 2024Article
- A heptavalent O-antigen bioconjugate vaccine exhibits differential functional antibody responses against diversebioRxiv : the preprint server for biology · 2023Article
- Hit 'em Where It Hurts: Gram-Negative Bacterial Lipopolysaccharide as a Vaccine Target.Microbiology and molecular biology reviews : MMBR · 2023Review
- Capsular polysaccharide inhibits vaccine-induced O-antigen antibody binding and function across both classical and hypervirulent K2:O1 strains of Klebsiella pneumoniae.PLoS pathogens · 2023Article
- Kaptive 2.0: updated capsule and lipopolysaccharide locus typing for theMicrobial genomics · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors.
Funding
Abstract
backgroundSafe and effective vaccines are urgently needed to prevent Klebsiella pneumoniae infections. We assessed safety and immunogenicity of a tetravalent bioconjugate vaccine Kleb4V, containing O antigen-polysaccharides of K. pneumoniae serotypes (O1v1, O2a, O2afg and O3b).
methodsIn this observer-blind, randomized, placebo-controlled, phase I/II trial (ClinicalTrials.gov NCT04959344), 166 healthy adults (16 aged 18-40 and 150 aged 55-70 years) were enrolled and randomized to receive 2 intramuscular injections of Kleb4V (16 or 64 μg of total O antigen with or without adjuvant AS03) or placebo on days 1 and 57. While the primary outcome was safety, the secondary outcomes included vaccine antigen immunogenicity.
resultsKleb4V was well tolerated, with most solicited and unsolicited AEs of mild to moderate intensity. Kleb4V was immunogenic for all four vaccine-serotypes at both doses. O1v1, O2a and O2afg specific IgG increased after the 1st vaccination and IgG persisted at six months after the second vaccination. For three of the four vaccine-serotypes, the AS03-adjuvanted formulations showed a superior immune response. O3b responses were reduced compared to the other vaccine antigens.
conclusionsKleb4V is the first K. pneumoniae conjugate vaccine candidate to reach clinical assessment. The Kleb4V bioconjugate was immunogenic and well tolerated in the target population of adults aged 55-70 years for the vaccine-serotypes.
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