CHAMGAP
VERIFIEDPassed the Codex final verification and publication gate. Evidence-verification cutoff: 2026-08-26. AI was used for research and drafting; the existence of all 3 cited sources was verified at the original page, followed by blind grading, adversarial audit, and build validation. Methodology v0.8.
Verdict No. 2929 · Search date 2026-08-26 · Methodology v0.8

MVA85A tuberculosis vaccine booster,
does it really help with Prevention of tuberculosis in BCG-vaccinated infants?

30-Second Summary
D
Evidence Grade D · 34 · Safety caution
MVA85A added after BCG did not reduce infant tuberculosis
Local adverse events were more frequent, 89% versus 45%. Systemic events were 80% versus 76%, serious events 18% versus 18%, and none of the serious events was vaccine-related.
What the
research shows
Grade D. Tuberculosis occurred in 32/1399 (2.3%) versus 39/1395 (2.8%), an absolute difference of -0.5 points; vaccine efficacy was 17.3% (95% CI -31.9 to 48.2).
What the
ads claim
BCG effectiveness and effectiveness of a post-BCG booster candidate must be separated.
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Useful facts when choosing a product

  • MVA85A is a modified vaccinia Ankara vector expressing antigen 85A.
  • All infants had received BCG.
  • Post-BCG boosters remain a genuine development target.
Gap Measurement · Verdict 2929 · D 34
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

BCG-vaccinated healthy infants were double-blind randomized and followed for up to 37 months. The Funding section listed Aeras, Wellcome Trust, and Oxford-Emergent Tuberculosis Consortium. MVA85A was developed at Oxford, with Emergent participating in the commercial development consortium.

02

Why this is classified as D (34)

One large null hard-outcome trial with a wide interval gives D with 34 points.

Counterpoint. The result does not negate BCG itself.

Rejudgment record. Cross-check applied — A 2,797-infant hard-outcome trial after BCG was null with a wide confidence interval

Scoring profile behind this grade
EndpointHHard endpoint - actual events such as death
ReplicationR1Single confirmatory trial
IndependenceI1Mixed funding sources
Effect sizeE0Null
PrecisionC0The confidence interval leaves room for benefit

The scoring table and the verdict agree (D).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Added TB prevention after BCGDNo significant benefit.

Cross-check — AI research and Codex final gate

AI was used for research and drafting. Blind grading, adversarial audit, and the methodology boundary rules were then reapplied before Codex performed the final evidence, grade, copy, and build checks. If a grade cannot be narrowed, both evidence positions and their reasons are published.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Double-blind placebo-controlled phase 2b RCT2,797Aeras, Wellcome Trust, and Oxford-Emergent Tuberculosis Consortium (OETC)Incident tuberculosis32/1399 vs 39/1395; efficacy 17.3% (95% CI -31.9 to 48.2), absolute difference -0.5 pointsLarge hard-outcome candidate-vaccine trial
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-08-26).

Tameris MD, et al. Lancet. 2013;381:1021-1028. PMID: 23391465.
checked
Reference 2
checked
Reference 3
checked
Research and draft: AI used · Cross-check: blind grading and adversarial audit
Final verification and publication gate: Codex · Verification cutoff: 2026-08-26 · Corrections: none

Cite this verdict

No Benefit of MVA85A Tuberculosis Vaccine for Preventing Tuberculosis in BCG-Vaccinated Infants Evidence Grade D card
[Chamgap] No Benefit of MVA85A Tuberculosis Vaccine for Preventing Tuberculosis in BCG-Vaccinated Infants — Evidence Grade D·34. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/mva85a-booster-bcg-vaccinated-infants-tuberculosis/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.