Safety of the novel oral poliovirus vaccine type 2 (nOPV2) in infants and young children aged 1 to <5 years and lot-to-lot consistency of the immune response to nOPV2 in infants in The Gambia: a phase 3, double-blind, randomised controlled trial.
Ochoge M, Futa AC, Umesi A, Affleck L, Kotei L, Daffeh B, Saidy-Jah E, Njie A, Oyadiran O, Edem B, Jallow M, Jallow E, Donkor SA, Tritama E, Abid T, Jones KAV, Mainou BA, Konz JO, Fix A, Gast C, Clarke E
- DOI
- 10.1016/S0140-6736(23)02844-1
- Record issued
- 2026-08-10
- Engine
- 7.29.0
- Exported
- 2026-09-22
Prepared by Alpha1. This document is confidential: it is intended for the recipient it was shared with and must not be redistributed. The live record at alpha1science.com/verify/a27bce4b-dd55-4ca4-9841-463f35cc0b6e is authoritative.
How this rating was calculated
- IntegrityIntegrity concern−0.5★
- StatisticsPrinted percentage does not match its own count (capped)−0.25★
- ReportingKey resources partially met−0.25★
- The numeric-impossibility checks (GRIM/GRIMMER/DEBIT/SPRITE) did not run on this paper: the pass that reads its reported means did not complete. No reported mean was checked for arithmetic impossibility.
- No data or code availability links were detected to verify.
- 01Printed percentage does not match its own count
74.4% does not match the reported count 1447/1949
“1447 (74.4%) of 1949”
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 rigorously designed and reported phase 3 RCT with strong scientific grounding, clear randomisation/blinding, documented ethics approvals, and a concrete data-sharing statement. The main weaknesses are minor reporting gaps: no statistical software is named, no CONSORT checklist is referenced, and there is a low-severity text-vs-table denominator discrepancy.
Both reviewers agreed on 7 of 8 dimensions; they diverged only on key resources (pass vs warn), which I resolved toward warn because statistical software is an applicable, unidentified resource. The statistics component recomputed only a subset (5 tests: 4 consistent, 1 text-vs-table denominator discrepancy); tests with threshold-only p-values or exact/resampling methods were not machine-verifiable and are neither confirmed nor refuted.
Numerical inconsistencies
2 findings · worst mediumValues 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.
- Printed percentage does not match its own countRecomputed
- Internal contradictions in the reported numbersAssessed
Recomputed 4 tests: 4 consistent, 0 inconsistent; 4 via agent-written checks. 1 printed percentage that does not match its own count.
- PERCENT74.4% does not match the reported count 1447/1949
“1447 (74.4%) of 1949”
- CONSISTENTreported p < .015 · recomputed p = .015Reviewer 1Two-tailed Fisher's exact test comparing rate of fever ≥37.5°C in infants receiving nOPV2 vs bOPV (reactogenicity population).
“fever of 37·5°C or higher was more common in infants following bOPV (26 [25·5%] of 102; 95% CI 17·4–35·1) than following nOPV2 (105 [15·4%] of 682; 12·8–18·3; p=0·015)”
Taken as given: 105 and 682 are the event count and total for the nOPV2 infant arm; 26 and 102 are the event count and total for the bOPV infant arm; the test is Fisher's exact two-tailed, as stated in the paper ('Fisher's exact two-tailed test of the rate of events between nOPV2 and bOPV'); the 682 and 102 denominators are the reactogenicity population for the two-dose infantsMethod: Fisher's exact two-tailed test on the 2×2 table (105/577 vs 26/76).How we recomputed it: pFisher2x2(105, 682-105, 26, 102-26, 0) - CONSISTENTreported p < .043 · recomputed p = .043Reviewer 1Two-tailed Fisher's exact test comparing rate of unsolicited adverse events within 28 days in infants receiving nOPV2 vs bOPV.
“837 (42%) of 2007 (95% CI 40–44) infants experienced an unsolicited adverse event within 28 days of nOPV2 administration compared with 161 (48%) of 338 (42–53) infants in the same time interval following bOPV (p=0·043; )”
Taken as given: 837 and 2007 are the event count and total for the nOPV2 infant safety population; 161 and 338 are the event count and total for the bOPV infant safety population; the test is Fisher's exact two-tailed, as stated in the paper; the 2007 and 338 denominators are the infant safety populationsMethod: Fisher's exact two-tailed test on the 2×2 table (837/1170 vs 161/177).How we recomputed it: pFisher2x2(837, 2007-837, 161, 338-161, 0) - CONSISTENTreported p = .015 · recomputed p = .015Reviewer 2Fisher's exact two-tailed p for the difference in fever (≥37.5°C) rates between nOPV2 and bOPV infants.
“fever of 37·5°C or higher was more common in infants following bOPV (26 [25·5%] of 102; 95% CI 17·4–35·1) than following nOPV2 (105 [15·4%] of 682; 12·8–18·3; p=0·015).”
Taken as given: the 105 and 682 are the nOPV2 fever cases and group total of the same arm; the 26 and 102 are the bOPV fever cases and group total of the same arm; non-events are computed as 682−105=577 and 102−26=76; the test is the two-tailed Fisher's exact test as stated in the Table 4 footnoteMethod: Two-tailed Fisher's exact test on the 2×2 table (105, 577, 26, 76).How we recomputed it: pFisher2x2(105, 577, 26, 76) - CONSISTENTreported p = .043 · recomputed p = .043Reviewer 2Fisher's exact two-tailed p for the difference in unsolicited adverse event rates within 28 days between nOPV2 and bOPV infants.
“837 (42%) of 2007 (95% CI 40–44) infants experienced an unsolicited adverse event within 28 days of nOPV2 administration compared with 161 (48%) of 338 (42–53) infants in the same time interval following bOPV (p=0·043; ).”
Taken as given: the 837 and 2007 are the nOPV2 event count and group total of the same arm; the 161 and 338 are the bOPV event count and group total of the same arm; non-events are computed as 2007−837=1170 and 338−161=177; the test is the two-tailed Fisher's exact test as stated in the Table 4 footnoteMethod: Two-tailed Fisher's exact test on the 2×2 table (837, 1170, 161, 177).How we recomputed it: pFisher2x2(837, 1170, 161, 177)
- lowinternal contradictionThe text reports infant baseline and post-dose-one seroprotection rates with a denominator of 1949, but the percentages are internally consistent with a denominator of 1946 (the nOPV2 group n in Table 3). This is a minor text-vs-table denominator discrepancy, not a demonstrable arithmetic error.
“The seroprotection rate at baseline in infants in the nOPV2 groups was 1447 (74·4%) of 1949 (95% CI 72·4–76·3) increasing to 1656 (85·1%; 83·4–86·7) post-dose one”
Table 3Find in source
Overstated conclusions
1 finding · worst lowConclusions 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
9 major claims checked against the paper's own evidence: all adequately supported.
- partialReviewer 1The vaccine is expected to effectively interrupt viral transmission while being associated with a considerably reduced risk of seeding further paralytic outbreaks.The reduced reversion risk rests on genetic-stability and prior-deployment evidence, and the transmission-interruption expectation is an extrapolation beyond this trial; the trial itself measured immunogenicity and shedding, not outbreak interruption.Evidence: Trial shedding data plus cited external genetic-stability and modelling/deployment data (Nigeria modelling, case–control effectiveness).
“When delivered through high-quality cVDPV2 outbreak response campaigns, the vaccine is expected to effectively interrupt viral transmission while being associated with a considerably reduced risk of seeding further paralytic outbreaks”
DiscussionFind in source - supportedReviewer 1Lot-to-lot equivalence of the three nOPV2 manufacturing lots was demonstrated.The pairwise 95% CIs for seroconversion-rate differences were entirely within the prespecified ±10% equivalence margin, directly supporting the claim.Evidence: Seroconversion rates of 48·9–49·2% across lots; the minimum CI lower bound was −5·8% and maximum upper bound 5·4%, within ±10%.
The minimum lower bound of the 95% CIs for the difference in seroconversion rates was –5·8%. The maximum upper bound was 5·4%. Equivalence was therefore shown.
Table 2reviewer’s wording - supportedReviewer 1nOPV2 was immunogenic and safe in infants and young children in The Gambia.Two-dose seroprotection rates of 92·9% (infants) and 95·5% (young children) and the absence of related severe/serious adverse events directly support the claim.Evidence: Post-two-dose seroprotection 604/650 (92·9%) in infants and 276/289 (95·5%) in young children; no severe or serious adverse events considered related to nOPV2.
“nOPV2 was immunogenic and safe in infants and young children in The Gambia.”
ResultsFind in source - supportedReviewers 1, 2The data support the licensure and WHO prequalification of nOPV2.The trial generated the safety and immunogenicity (including lot-to-lot consistency) data that the authors state are required for licensure/prequalification; the claim is appropriately framed as the data supporting the decision, not as a decision already made.Evidence: Lot-to-lot equivalence, two-dose seroprotection ≈95%, and contemporaneous double-blind safety comparison with bOPV.
“The data support the licensure and WHO prequalification of nOPV2 as a vital tool in the polio eradication endgame strategy.”
DiscussionFind in source - supportedReviewer 1The immunogenicity of nOPV2 in this trial is consistent with mOPV2 data from comparable sub-Saharan African settings.The claim is backed by direct comparison with a Mozambique mOPV2 trial (two-dose seroconversion 60·6%) and the acknowledgement of lower rates in non-temperate settings.Evidence: Mozambique mOPV2 type 2 seroconversion of 83/137 (60·6%) vs two-dose nOPV2 seroconversion rates of 66·7% (infants) and 73·8% (young children) in this trial.
“Thus, the immunogenicity of nOPV2 in this trial is consistent with data for mOPV2 from comparable settings in sub-Saharan Africa.”
DiscussionFind in source - supportedReviewer 1A rapid decrease in faecal shedding of the virus in infants was shown.Shedding fell from 42% at day 7 to 4% at day 28 and none at day 84, directly supporting the claim of a rapid decrease.Evidence: 78/187 (42%) excreting type 2 virus at day 7, 8/186 (4%) at day 28, none at day 84; median time to cessation 7 days.
“By 28 days following vaccination this decreased to 8 (4%) of 186 (95% CI 2–8). No type 2 poliovirus was detected 84 days following vaccination.”
DiscussionFind in source - supportedReviewer 2Lot-to-lot equivalence of the three nOPV2 lots was shown based on one-dose type 2 seroconversion rates.The primary endpoint analysis directly supports equivalence: all three pairwise 95% CIs (−5.5 to 5.4, −5.8 to 5.1, −5.7 to 5.2) lie within the −10% to 10% margin.Evidence: Table 2 pairwise seroconversion rate differences and 95% CIs; the min lower bound −5.8% and max upper bound 5.4%.
The minimum lower bound of the 95% CIs for the difference in seroconversion rates was –5·8%. The maximum upper bound was 5·4%. Equivalence was therefore shown.
Table 2reviewer’s wording - supportedReviewer 2nOPV2 was immunogenic in infants and young children in The Gambia.Seroconversion and seroprotection rates with CIs are presented for both age groups, supporting immunogenicity.Evidence: Post-two-dose seroconversion 85.6% (143/167) in infants and 83.1% (54/65) in young children; post-two-dose seroprotection 92.9% and 95.5%.
“Of those seronegative at baseline, 143 (85·6%) of 167 (95% CI 79·4–90·6) infants and 54 (83·1%) of 65 (71·7–91·2) young children seroconverted over the two-dose nOPV2 schedule.”
AbstractFind in source - supportedReviewer 2nOPV2 was safe in infants and young children in The Gambia.The contemporaneous double-blind comparison with bOPV plus the absence of related severe/serious events supports the safety claim, with the caveat of limited power for rare events which the authors acknowledge.Evidence: Reactogenicity and safety tables; no serious/severe events judged related to nOPV2; one severe solicited fever in a bOPV recipient.
“There were no severe or serious adverse events after nOPV2 that were considered to be related to the vaccines.”
Table 4Find in source
Data authenticity concerns
None foundAn 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.
Checked — nothing surfaced.
Reporting gaps
1 finding · worst mediumRequired detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.
- Key resources under-identified (antibodies, cell lines, RRIDs)Assessed
Prior work is extensively cited (phase 1/2 trials in Belgium, Panama, Bangladesh; historical mOPV2 controls; Emergency Use Listing rollout data), with both strengths and the genetic-stability rationale acknowledged. The rationale linking the vaccine's engineered genetic stability to the need for licensure/prequalification data is explicit, and the trial is framed to address the gap of no prior African data. The Discussion notes limitations of prior work (e.g., lower immunogenicity in non-temperate settings) and contextualises the trial against them.
“In clinical trials done in adults (ie, those aged 18–50 years) in Belgium, in infants (ie, those aged 18–22 weeks) and children (ie, those aged 1–4 years) in Panama, and newborns in Bangladesh, the vaccine has been shown to be well tolerated and safe.”
“This phase 3 trial aimed to generate the data required for nOPV2 licensure and for its prequalification by WHO.”
“This clinical trial is the first of nOPV2 in Africa, which has had the greatest burden of cVDPV2 since trivalent OPV withdrawal.”
“Novel oral poliovirus vaccine type 2 (nOPV2) has been engineered to increase the genetic stability of type 2 Sabin oral poliovirus vaccine (OPV) and hence to reduce the risk of paralytic outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2).”
“This phase 3 trial aimed to generate the data required for nOPV2 licensure and for its prequalification by WHO.”
For a human phase 3 RCT, the applicable criteria are met. Randomisation used permuted blocks generated by an independent statistician with a web-based system; the unit is the individual participant. Blinding is double-blind with unmasked nurses only for preparation/administration. An a priori power calculation (670 infants per nOPV2 group for ≥90% power with a −10% to 10% equivalence margin) is given. Eligibility criteria and the per-protocol/safety analysis populations are defined. Outlier handling maps to the pre-specified PP and safety populations. Bench-science criteria (replicate_distinction, controls, independent_replication) are not applicable to a human RCT.
“Randomisation sequences were generated by an independent statistician using permuted block sizes. Vaccine assignment was undertaken using a web-based randomisation system.”
“Only unmasked nurses who were responsible for vaccine preparation and administration were aware of the vaccine assigned. Parents and all other staff were masked.”
“Randomisation sequences were generated by an independent statistician using permuted block sizes. Vaccine assignment was undertaken using a web-based randomisation system. Only unmasked nurses who were responsible for vaccine preparation and administration were aware of the vaccine assigned.”
“Healthy infants, who had received at least three doses of bOPV and a single dose of the inactivated poliovirus vaccine at least one month before randomisation, were eligible to join the study from aged 18 weeks until the day before they reached age 52 weeks.”
Sex is reported (approximately 49% female in both cohorts), age (median at screening per group) and weight-for-height Z-scores (malnutrition status) are reported, and race (Black African) and ethnicity breakdowns are given. Both sexes were enrolled, so a sex justification is not applicable. Species/strain and housing are not applicable for this human trial.
“1154 (49·2%) of 2345 infants and 296 (49·3%) of 600 young children were female.”
“Between 5·0% and 9·3% of infants and children were at least moderately malnourished (weight for height Z score of <–2 SD).”
“Black African | 1322 (99·8%) | 236 (100%) | 682 (100%) | 102 (100%) | 300 (100%) | 300 (100%)”
“1154 (49·2%) of 2345 infants and 296 (49·3%) of 600 young children were female.”
“Median age at screening (minimum to maximum value) | 33 weeks (18 to 52) | 30 weeks (21 to 52)”
Approval is explicitly reported from four named bodies including The Gambia Government/MRC joint ethics committee (with protocol number LEO22052) and the LSHTM Research Ethics Committee. Parental written informed consent is documented. Regulatory compliance with the Declaration of Helsinki and Good Clinical Practice is stated by name.
“Approval was obtained from The Gambia Government and MRC joint ethics committee (LEO22052), the London School of Hygiene and Tropical Medicine Research Ethics Committee, the WIRB-Copernicus Group Institutional Review Board, and The Gambian Medicines Control Agency.”
“Parents provided written informed consent.”
“The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines.”
“Approval was obtained from The Gambia Government and MRC joint ethics committee (LEO22052), the London School of Hygiene and Tropical Medicine Research Ethics Committee, the WIRB-Copernicus Group Institutional Review Board, and The Gambian Medicines Control Agency.”
“Parents provided written informed consent.”
“The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines.”
For a vaccine trial, the investigational products are scored under reagents_identified: nOPV2 (PT Biofarma) with batch numbers 2220720, 2220820, 2220920 and dose, and bOPV (PT Biofarma, batch 2045119) are adequately identified. However, the statistical software used for analysis is not named anywhere in the Statistical analysis section, leaving software_tools_identified not_reported. With 1 of 2 applicable criteria adequate, the dimension is a warn. The microneutralisation assay is identified (WHO EPI Gen 93.9); bench criteria (antibodies, cell lines, mycoplasma, organisms) are not applicable to this human vaccine trial.
“A single 0·1 mL (two drop) dose of nOPV2 (PT Biofarma, Bandung, Indonesia) contains at least 10 5·0 50% cell culture infectious dose (CCID 50 ) of the nOPV2 strain. The batch numbers for lots 1, 2, and 3 were 2220720, 2220820, and 2220920 respectively.”
“20-dose vials with a batch number of 2045119 were used in the trial.”
“The batch numbers for lots 1, 2, and 3 were 2220720, 2220820, and 2220920 respectively.”
Tests are named (Miettinen and Nurminen CIs, exact Clopper-Pearson CIs, Fisher's exact test, bootstrap percentile CIs). Reported p-values (0.015, 0.043) are exact and recomputable via Fisher's exact test from the stated cell counts. Effect estimates are reported with 95% CIs throughout, satisfying reporting-by-estimation norms. Data presentation uses rates with exact CIs and per-group n. Software is not identified (also flagged under key_resources). mathematical_plausibility is not_applicable for this large-N trial with continuous/rate outcomes. Two Fisher exact p-values were recomputed and were consistent.
“To show lot-to-lot equivalence, two-sided 95% Miettinen and Nurminen CIs for the differences in seroconversion rates between pairs of each of the three nOPV2 lots were calculated.”
“than following nOPV2 (105 [15·4%] of 682; 12·8–18·3; p=0·015)”
“To show lot-to-lot equivalence, two-sided 95% Miettinen and Nurminen CIs for the differences in seroconversion rates between pairs of each of the three nOPV2 lots were calculated.”
“fever of 37·5°C or higher was more common in infants following bOPV (26 [25·5%] of 102; 95% CI 17·4–35·1) than following nOPV2 (105 [15·4%] of 682; 12·8–18·3; p=0·015).”
The data-sharing statement describes a managed-access route: de-identified individual participant data available from 3 months to 3 years after publication, with proposals directed to the corresponding author, review by funder/investigators, and a data access agreement. This meets the 'concrete route with conditions and timeframe' tier. repository_deposit and accession_numbers are not applicable to identifiable patient-level data; no bespoke code is involved so code_sharing is not applicable.
“The individual participant data that underlie the results reported in this Article, after de-identification (ie, text, tables, figures, and appendices), will be shared. They will be available beginning 3 months and ending 3 years after publication.”
“Researchers who provide a scientifically sound proposal will be allowed access to the individual participant data. Proposals should be directed to the corresponding author.”
“They will be available beginning 3 months and ending 3 years after publication. Supporting clinical documents including the study protocol, statistical analysis plan, and the informed consent form will be available immediately following publication on application to the corresponding author.”
Six of seven applicable criteria are adequate: methods are detailed enough to replicate; the trial is registered (PACTR202010705577776); all pre-specified outcomes are reported; limitations are explicitly discussed; conclusions are proportional to the evidence; and funding (Bill & Melinda Gates Foundation OPP1150001) plus COI declarations are provided. No CONSORT checklist is explicitly referenced, leaving reporting_guideline not_reported.
“The trial was registered with the Pan-African Clinical Trials Registry (PACTR202010705577776).”
“The trial was funded by the Bill & Melinda Gates Foundation (grant OPP1150001).”
“The trial was registered with the Pan-African Clinical Trials Registry (PACTR202010705577776).”
“First, the absence of an active control vaccine for the type 2 immunogenicity and viral excretion data was unavoidable given the restrictions on the usage of the type 2 Sabin OPV.”
Registration stated in text, but no registry ID was detected. No reporting guideline cited.
Broken references and links
None found · partly checkedReferences checked against Crossref, OpenAlex and Retraction Watch for retractions and resolvability, plus declared data and code links probed for whether they resolve to content matching the paper.
Nothing surfaced — but not everything feeding this category ran (missing: data/code link verification), so read this as a partial clean bill.
Checked 32 references by DOI: 26 verified — 6 no DOI (shown, not verified).
- NO DOIPolio todayNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIPolio eradication strategy 2022–2026: delivering on a promiseNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOICirculating vaccine-derived polioviruses, global updateNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOICirculating vaccine-derived poliovirusesNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIFirst ever vaccine listed under WHO emergency useNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOI820 million novel polio vaccinations completedNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
Copyediting
9 minorWording, consistency and formatting errors that need correcting before submission.
No major wording or formatting errors. 9 minor suggestions below.
9 copyedit issues flagged: mostly grammar, consistency, other.
- MINORgrammarSummary/Methods“Infants randomly assigned to receive one or two doses of one of three lots of nOPV2”→ Infants were randomly assigned to receive one or two doses...Missing auxiliary verb 'were'.
- MINORpunctuationResults (young children GMT)“and 1151·8 (774·6–1712·6) post-dose two (12·0; 9·2–15·6]).”→ Remove the stray closing bracket: '...9·2–15·6).'Stray ']' after the CI.
- MINORgrammarIntroduction“although there were less than 100 cVDPV type 2 (cVDPV2) cases in two countries in 2017”→ although there were fewer than 100 cVDPV type 2 (cVDPV2) cases...'Less than' is used for uncountable quantities; countable cases take 'fewer than'.
- MINORgrammarMethods, Procedures“A single 0·1 mL (two drop) dose of nOPV2”→ A single 0·1 mL (two-drop) dose of nOPV2Compound adjective should be hyphenated.
- MINORclaritySummary/Methods“The trial was registered as PACTR202010705577776 and is completed.”→ The trial was registered as PACTR202010705577776 and is complete.Awkward phrasing 'is completed'.
- MINORconsistencyResults“The one dose seroconversion rate in infants who were seronegative at baseline”→ The one-dose seroconversion rate in infants who were seronegative at baselineInconsistent hyphenation of 'one dose' vs 'one-dose' across the manuscript.
- MINORconsistencyResults“1447 (74·4%) of 1949”→ Confirm whether the denominator is 1946 (as in Table 3) or 1949; the stated percentages are consistent with 1946.Denominator mismatch between text and Table 3.
- MINORotherMethods, Procedures“A single 0·1 mL (two drop) dose of nOPV2 (PT Biofarma, Bandung, Indonesia) contains at least 10 5·0 50% cell culture infectious dose (CCID 50 )”→ Restore superscript formatting: '10^5.0 50% cell culture infectious dose (CCID50)'.Superscript rendering artifact in the plain-text version.
- MINORotherMethods, Procedures“A single 0·1 mL (two drop) dose of bOPV (PT Biofarma) contains at least 10 6.0 CCID 50 of Sabin type 1 poliovirus and at least 10 5.8 of Sabin type 3 poliovirus.”→ Restore superscript formatting for the CCID50 values.Superscript rendering artifact in the plain-text version.
The published work is robust: the core safety and lot-to-lot equivalence conclusions are well supported by the reported design, ethics, and data-sharing transparency. An informed reader should weigh the minor reporting gaps — the unnamed statistical software, the absent CONSORT reference, and the 1949-vs-1946 denominator discrepancy — none of which undermines the main findings; the denominator discrepancy is worth a correction, and the other two are best-practice omissions rather than validity threats.
- 1.HIGHstatisticsReconcile the denominator in Results: the text reports 1447 (74·4%) of 1949, but the percentages are consistent with a denominator of 1946 (the nOPV2 group n in Table 3); correct the text or the table to match.A text-vs-table denominator discrepancy is a verifiable internal inconsistency that could mislead readers about the seroprotection rates.
- 2.HIGHreportingName the statistical software and version used for all analyses in the Methods, Statistical analysis section.Identifying the analysis software is a reproducibility requirement and is the sole reason key_resources is not a clean pass.
- 3.MEDIUMreportingAdd an explicit statement that the trial is reported in accordance with the CONSORT 2010 checklist, and reference the checklist.A published phase 3 RCT should cite the applicable reporting guideline; its absence is a transparency gap reviewers will note.
- 4.MEDIUMcopyeditIn the Summary/Methods, change 'Infants randomly assigned to receive' to 'Infants were randomly assigned to receive'.Missing auxiliary verb is a grammar error in the abstract.
- 5.MEDIUMcopyeditFix the stray closing bracket in Results (young children GMT): '...post-dose two (12·0; 9·2–15·6]).' should end with a single closing parenthesis.A stray bracket impairs readability of a reported confidence interval.
- 6.MEDIUMcopyeditIn the Introduction, change 'there were less than 100 cVDPV type 2 (cVDPV2) cases' to 'fewer than 100'.Countable cases take 'fewer than', not 'less than'.
- 7.MEDIUMcopyeditHyphenate compound adjectives: 'two drop' → 'two-drop' and 'one dose seroconversion' → 'one-dose seroconversion' consistently throughout.Inconsistent hyphenation of compound modifiers reduces editorial quality.
- 8.MEDIUMcopyeditIn the Summary/Methods, change 'is completed' to 'is complete'.Awkward phrasing in the trial-status statement.
- 9.MEDIUMcopyeditRestore superscript formatting for the CCID50 values in Methods, Procedures (e.g., '10 5·0' → '10^5.0', and the bOPV CCID50 values).Superscript rendering artifacts obscure the reported virus doses.
The star rating is the report’s one-glance summary. Every paper starts at 5★ and loses stars for the concrete problems the review finds — so a rating is never a vague average, it’s a running total you can read line by line under “How this rating was calculated.”
- Reporting — 8 dimensionseach dimension that fully fails−½★
- each dimension partially met−¼★
- Statistics · Integrity · Claimseach serious problem−1★
- each medium problem−½★
- Citationseach retracted or unverifiable reference−¼★
- Copyeditonly when the manuscript needs a full edit−½★
The rating never drops below 1★, and a demonstrable critical failure (an impossible statistic, a proven ethics violation) caps it at 1★ on its own — so the stars can never look healthy when the verdict is CRITICAL.
The rating draws on a panel of agents. Three independent Kaimen Rigor reviewers grade the eight dimensions below across several independent passes (the shown verdict is their majority vote — steadier than any single run), isolate the paper’s major claims and check its own evidence backs them, and flag integrity concerns. Alongside them, a citation agent resolves every reference against Crossref, OpenAlex, and Retraction Watch; a statistics agent recomputes reported tests; and rule-based checks verify that declared data/code links actually resolve. Full text is required — an abstract-only submission is not analyzed.
Graded against NIH, MDAR, ARRIVE 2.0, CONSORT, EQUATOR, and RRID guidelines. A dimension that doesn’t apply to the study type is skipped, never penalized.
This Kaimen Rigor review is model-assisted and is not a substitute for formal expert review. It complements human evaluation by surfacing potential methodological concerns — verify each finding against the source.