A multi‐country cluster randomized controlled effectiveness evaluation to accelerate the introduction of Vi polysaccharide typhoid vaccine in developing countries in Asia: rationale and design
Bibliographic record
Abstract
Phase-III vaccine efficacy trials typically employ individually randomized designs intended to ensure that measurements of vaccine protective efficacy reflect only direct vaccine effects. As a result, decisions about introducing newly licensed vaccines into public health programmes often fail to consider the substantially greater protection that may occur when a vaccine is deployed in public health programmes, due to the combination of direct plus indirect vaccine protective effects. Vaccine total protection can be better evaluated with cluster randomized trials. Such a design was considered to generate policy relevant data to accelerate the rationale introduction of the licensed typhoid fever Vi polysaccharide (PS) vaccine in Asia by the Diseases of the Most Impoverished (DOMI) typhoid fever programme. The DOMI's programme multi-country study is one of the largest cluster randomized vaccine trials ever mounted in Asia, which includes approximately 200,000 individuals. Its main objective is to determine the effectiveness of a licensed Vi PS vaccine. The rationale and design of this study are discussed. Preliminary results are presented that determined the final planning of the trial before immunization. Important methodological and practical issues regarding vaccine cluster randomized designs are illustrated.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.162 | 0.163 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.006 | 0.006 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.002 | 0.004 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.006 | 0.003 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".