Method

These narrative reviews cover a 15-year publication window: Sept 2011 – Sept 2026. The evidence cutoff remains September 2026; the window was expanded on 23 October 2026.

Scope: the 15 existing topics were revisited to add earlier trials, reviews and implementation studies, including null results and harms. This is a targeted narrative review, not an exhaustive systematic review or a new meta-analysis.
Dates: eligibility follows publication date, using first online publication where available, rather than the dates when participants were studied. Reviews published within the window can include earlier trials. Sources predating September 2011 are labelled as historical background.
Sources: peer-reviewed studies and evidence reviews support research findings. WHO guidance, programme reports and trial registries supply policy and implementation context. Preprints are labelled as not yet peer-reviewed; protocols are not results.
Verification: for the October expansion, 35 added papers were checked against their PubMed-indexed Europe PMC records and reported estimates against their abstracts. Earlier sources already cited were revisited where they affected the interpretation; WHO guidance was checked separately. This update is not a fresh verification of every existing claim or registry status.
Interpretation: mortality, disease, carriage and care-seeking are different outcomes. Follow-up reports and reviews may share participants; their results are not independent replications. Null results, harms, uncertainty and manufacturer funding are discussed alongside benefits.
Article dates: the displayed article date is an editorial date based on the newest research paper covered, not the date the page first went online. We use 75 days after that paper's first online publication, within our 60–90-day target. If that would be in the future when we assign the date, we use the earlier of 10 days after the paper or the assignment day. The date is saved and does not move as time passes. Studies, evidence reviews, covered preprints and research protocols count; standalone corrections, registry entries, guidance and news do not set this date. The latest research date links to the corresponding source.
Revisions: substantive changes receive an actual updated date, and corrections are recorded separately. Adding a newer research paper requires reassessing the article date under the same rule. The October revision date does not extend the September evidence cutoff.
Tools: research and writing are AI-assisted. Source verification is not a claim of independent clinical or peer review.