Controlled Human Infection of Healthy Adults With Lyophilized Neisseria lactamica Induces Asymptomatic, Immunogenic Nasopharyngeal Carriage in the United Kingdom and Mali - Summary - MDSpire

Controlled Human Infection of Healthy Adults With Lyophilized Neisseria lactamica Induces Asymptomatic, Immunogenic Nasopharyngeal Carriage in the United Kingdom and Mali

  • By

  • D F Gbesemete

  • F Haidara

  • J R Laver

  • M Ibrahim

  • J MacLennan

  • A P Dale

  • A R Gorringe

  • Y Traore

  • F Diallo

  • H Badji

  • A Traore

  • U Onwuchekwa

  • E Jones

  • C Webb

  • J Guy

  • A A Theodosiou

  • S N Faust

  • S O Sow

  • R S Heyderman

  • M D Tapia

  • R C Read

  • January 7, 2026

  • 0 min

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Objective:

To evaluate the safety and colonization efficacy of lyophilized Neisseria lactamica (LyoNlac) in healthy adults and its potential to induce immune responses that may help reduce Neisseria meningitidis (Nmen) carriage.

Key Findings:
  • LyoNlac was well tolerated with no significant safety concerns.
  • In the UK, 105 CFU resulted in 100% colonization (n = 10/10), while in Mali, 107 CFU achieved 65% colonization (n = 13/20), indicating varying efficacy based on dosage and location.
  • Colonized participants showed increased Nlac- and Nmen-specific IgG levels post-challenge.
Interpretation:

Intranasal inoculation with LyoNlac is safe and effectively induces nasopharyngeal colonization and immune responses in healthy adults, suggesting its potential for reducing Nmen carriage and improving public health outcomes.

Limitations:
  • The study was limited to healthy adults aged 18–45 years, which may not represent broader populations, particularly vulnerable groups.
  • The long-term effects of LyoNlac on meningococcal carriage and transmission remain to be evaluated, which could impact its applicability in real-world settings.
Conclusion:

Future clinical trials are warranted to assess the impact of LyoNlac on meningococcal carriage and transmission in the meningitis belt, particularly focusing on diverse populations and long-term outcomes.

Original Source(s)

Controlled Human Infection of Healthy Adults With Lyophilized Neisseria lactamica Induces Asymptomatic, Immunogenic Nasopharyngeal Carriage in the United Kingdom and Mali

  • by D F Gbesemete, F Haidara, J R Laver, M Ibrahim, J MacLennan, A P Dale, A R Gorringe, Y Traore, F Diallo, H Badji, A Traore, U Onwuchekwa, E Jones, C Webb, J Guy, A A Theodosiou, S N Faust, S O Sow, R S Heyderman, M D Tapia, R C Read

  • January 7, 2026

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