Controlled Human Infection of Healthy Adults With Lyophilized <i>Neisseria lactamica</i> Induces Asymptomatic, Immunogenic Nasopharyngeal Carriage in the United Kingdom and Mali
Bibliographic record
Abstract
Abstract Background Carriage of Neisseria lactamica (Nlac), a harmless nasopharyngeal commensal, correlates inversely with carriage of Neisseria meningitidis (Nmen), a common cause of meningitis and sepsis outbreaks in sub-Saharan Africa. Nasally administered lyophilized Nlac (LyoNlac) might interrupt carriage and transmission of Nmen in sub-Saharan settings without requirement of a cold chain, but whether LyoNlac can establish colonization is undetermined. Methods Healthy adult volunteers aged 18–45 years were inoculated intranasally with 104–107 colony forming units (CFU) of reconstituted, lyophilized Nlac strain Y92-1009 (LyoNlac) in 2 dose-ranging controlled human infection studies conducted in the United Kingdom and Mali. Safety was measured as a primary objective. Secondary objectives included the dose achieving ≥70% colonization rates for each setting, colonization kinetics, and serological responses. Both trials were registered with ClinicalTrials.gov (United Kingdom: NCT04135053, Mali: NCT04665791) and are complete. Results Intranasal inoculation with LyoNlac was well tolerated with no significant safety concerns. In the United Kingdom, 105 CFU yielded 100% colonization (n = 10/10) while in Mali, 107 CFU achieved 65% colonization (n = 13/20). An increase in Nlac- and Nmen-specific IgG from pre-challenge to day 28 post-challenge was observed in colonized participants—median fold-change [interquartile range] United Kingdom: Nlac 2.24 [1.37–4.24], Nmen 1.39 [1.20–3.70] and Mali: Nlac 1.31 [1.04–1.94], Nmen 1.32 [0.99–1.73]. No significant seroconversion occurred in non-colonized participants. Conclusions Intranasal inoculation with LyoNlac was safe and induced immunogenic nasopharyngeal colonization in healthy adults in the United Kingdom and Mali. Future clinical trials to determine whether LyoNlac reduces meningococcal carriage and transmission in the meningitis belt are warranted.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
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".