Kaimen Rigor reviewed

Rigor-Reviewed Manuscript

A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.

Name: Kaimen Rigor review — A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.
Item: A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.
Rating: 59
Author: Alpha1

Chen WH, Barnes RS, Sikorski MJ, Datar R, Sukhavasi R, Liang Y, Rapaka RR, Pasetti MF, Sztein MB, Wahid R, Tennant SM, Simon R, Baliban SM, Galen JE, Lees A, Bernshtein B, Alter G, Ella R, Mohan K, Naidu MG, Rao DY, Ella KM, Levine MM

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Kaimen Rigor review — 2.75★ (Weak), 0 critical, 5 high issues for “A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.”

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Alpha1 Editorial

This rigor review was examined and confirmed by Alpha1 Editorial · August 15, 2026

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A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.

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DOI

10.1038/s41591-025-04003-z

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Issued Aug 15, 2026Engine 7.39.0

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Kaimen Rigor reviewed

Rigor-Reviewed Manuscript

A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.

Paper source

A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.

Read full text (PMC)

Embed this Rigor badge

Links back to this Kaimen Rigor review.

Alpha1 Editorial

This rigor review was examined and confirmed by Alpha1 Editorial · August 15, 2026

Kaimen Rigor review

Kaimen Rigor reviewed

2.75 / 5

Weak — serious problems found

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

IntegrityIntegrity concern ×2−1★
StatisticsStatistic did not reproduce−0.5★
ReportingStudy design partially met−0.25★
ReportingStatistical analysis partially met−0.25★
ReportingData & code availability partially met−0.25★

Model-reported confidence: highReviewer agreement: moderateEngine: 7.39.0Source: full text

Biggest issues

01Printed percentage does not match its own count
highArithmeticrecomputedFull detail
100% does not match the reported count 5/7
“100% (5/7)”
Antigen-specific serum IgG ELISA respon…

Findings by category

201ArithmeticNumerical inconsistencies 102OverreachOverstated conclusions 103AuthenticityData authenticity concerns 304DisclosureReporting gaps 05AvailabilityNone found 06Copyedit10 minor suggestions

This Kaimen Rigor review uses Kaimen Rigor reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

This is a well-conducted first-in-human phase 1 trial of a trivalent Salmonella conjugate vaccine, with strong scientific premise, adequate ethical approvals, and transparent reporting. The main weaknesses are incomplete reporting of randomization and blinding details, lack of a formal power analysis, imprecise statistical reporting (threshold p-values, no effect sizes with CIs), and a vague data availability statement.

All three reviewers classified the study as interventional, and this was adopted. The evaluation covered the full text, with verification components checking citations (32 references, none retracted or missing), statistics (2 tests recomputed, 1 consistent, 1 inconsistent), reproducibility (2 links live), and preregistration (ClinicalTrials.gov, CONSORT). The statistics coverage is limited to tests with test statistics and df; threshold-only p-values and resampling-based tests were not machine-verified. The reviewers diverged on study design and statistical analysis (pass vs. warn), but the synthesized status is warn based on the checklist-level gaps.

Numerical inconsistencies

2 findings · worst high

Values that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.

Summary statistic impossible for the stated N (GRIM/GRIMMER)Recomputed
Internal contradictions in the reported numbersAssessed

Recomputed 1 test: 1 consistent, 0 inconsistent; 1 via agent-written checks. 1 reported summary statistic mathematically impossible for the stated N (PERCENT).

Overstated conclusions

1 finding · worst low

Conclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.

Conclusions only partially backed by the presented evidenceAssessed

12 major claims checked against the paper's own evidence: 4 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.

Data authenticity concerns

1 finding · worst low

An adversarial read for patterns associated with data that may not be genuine: results that look too clean, implausibly large effects, duplicated data or images, and methods that do not match the results reported.

Other integrity concernAssessed

2 integrity concerns flagged (0 high).

Reporting gaps

3 findings · worst high

Required detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.

Statistical reporting gaps (tests, assumptions, effect sizes)Assessed
Data/code availability incompleteAssessed
Study-design details incomplete (controls, blinding, power)Assessed

Eight Dimensions5 pass · 3 warn

The introduction extensively cites epidemiological data on iNTS and typhoid burden, prior vaccine development efforts, and preclinical studies in mice and rabbits demonstrating immunogenicity and protection. The rationale for combining Vi-TT with iNTS COPS:FliC conjugates is logically presented. Limitations of prior work (e.g., lack of a combined vaccine, need for a vaccine suitable for infants) are implicitly addressed by the study's objectives, though not explicitly discussed as limitations of prior research.

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedINADEQUATE

Per reviewer (3) — the votes behind the verdict

PASSReviewer 1· 90% conf

The paper establishes a strong scientific premise by citing the burden of invasive non-typhoidal Salmonella and typhoid in sub-Saharan Africa, prior preclinical studies, and the rationale for a trivalent vaccine.

Evidence

“In 2017 it was estimated that globally ˜535,000 cases of iNTS disease occurred in persons not infected with HIV, of which ˜421,600 transpired in SSA, accompanied by ˜66,520 deaths.”

Introduction ¶1Find in source

“Preclinical studies in mice and rabbits demonstrated robust immunogenicity to the respective COPS and flagellin antigens after immunization with the iNTS conjugates.”

Introduction ¶4Find in source

“It is thus advantageous to consider a Trivalent Salmonella Conjugate Vaccine (TSCV) that would confer protection against both typhoid and iNTS disease.”

Introduction ¶3Find in source

PASSReviewer 2· 95% conf

The paper clearly establishes the scientific premise by citing the high burden of invasive non-typhoidal Salmonella and typhoid disease in sub-Saharan Africa, the need for a combined vaccine, and prior preclinical work supporting the TSCV approach.

Evidence

“In 2017 it was estimated that globally ˜535,000 cases of iNTS disease occurred in persons not infected with HIV, of which ˜421,600 transpired in SSA, accompanied by ˜66,520 deaths.”

Introduction ¶1Find in source

“Preclinical studies in mice and rabbits demonstrated robust immunogenicity to the respective COPS and flagellin antigens after immunization with the iNTS conjugates.”

Introduction ¶4Find in source

absence[Introduction]

The paper does not explicitly discuss limitations of prior research that the current study addresses.

PASSReviewer 3· 90% conf

The paper establishes a strong scientific premise with extensive prior work and a clear rationale for the vaccine.

Evidence

“In 2017 it was estimated that globally ˜535,000 cases of iNTS disease occurred in persons not infected with HIV, of which ˜421,600 transpired in SSA, accompanied by ˜66,520 deaths.”

Introduction ¶1Find in source

“The reason is that the conjugation procedure employed in the manufacture of TSCV inactivates the TLR-activating moiety of FliC.”

Discussion ¶5Find in source

“It is thus advantageous to consider a Trivalent Salmonella Conjugate Vaccine (TSCV) that would confer protection against both typhoid and iNTS disease.”

Introduction ¶3Find in source

The paper states 'No formal power calculations or hypothesis testing was performed' and that the sample size was deemed appropriate for a first-in-human study. Randomization method is not described (e.g., computer-generated sequence, block size). Blinding is stated as double-blind, but details on who was blinded (participants, investigators, assessors) are not provided. Inclusion/exclusion criteria are referenced to the protocol but not fully detailed in the paper. The pandemic led to missing data and incomplete follow-up, which is a limitation but not a design flaw per se. For a human RCT, replicate_distinction, controls (wet-lab), and independent_replication are not applicable.

Sub-criteria

controlsN/A

power analysisNOT REPORTED

blinding levelsINADEQUATE

outlier handlingNOT REPORTED

randomization unitADEQUATE

inclusion exclusionINADEQUATE

randomization methodNOT REPORTED

replicate distinctionN/A

independent replicationN/A

Per reviewer (3) — the votes behind the verdict

PASSReviewer 1· 85% conf

The trial design is appropriate for a phase 1 study, with randomization, blinding, and a stepwise dose-escalation, though the sample size is small and no formal power calculation was performed.

Evidence

“This first-in-human, randomized, double-blinded, placebo-controlled, phase 1 trial enrolled a total of 22 adult male and non-pregnant female participants, aged 18-45 years.”

A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.

A combination typhoid and non-typhoidal Salmonella polysaccharide conjugate vaccine in healthy adults: a randomized, placebo-controlled phase 1 trial.

Numerical inconsistencies

Overstated conclusions

Data authenticity concerns

Reporting gaps

Broken references and links

Copyediting

Numerical inconsistencies

Overstated conclusions

Data authenticity concerns

Reporting gaps

Broken references and links

Copyediting