An interventional study of Intranasal inoculation with Neisseria lactamica in Meningitis, Meningococcal, sponsored by Center for Vaccine Development - Mali. Completed at 1 site in Mali. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-03-27.
Sponsored by Center for Vaccine Development - Mali · Not applicable, Interventional, and Basic science
This study is part of a series of projects to improve protection against meningitis. Previously, researchers have given nose drops containing N. lactamica to over 400 volunteers and shown that many of them become colonised with N. lactamica without causing any illness or disease. This has previously been shown to prevent people from becoming colonised with N. meningitidis which can cause meningitis. This study aims to give nose drops containing N. lactamica to healthy adults in Mali, to see if they become safely colonised. In the future the study team would like to find out how N.lactamica helps children resist N.meningitidis, and develop new vaccines that exploit that mechanism.
In this pilot research, the study team will use a methodology of nasal inoculation with reconstituted lyophilised N. lactamica (hereafter LyoNlac) developed in a previous, UK-based, human challenge study. This methodology and will be developed further and validated in healthy Malian adults.
A dose-ranging strategy will be used, starting with the dose identified as the standard inoculum in healthy adults in the UK, which was the dose required to induce colonisation in approximately 80% of volunteers. The dose will be escalated to a dose able to induce a similar level of colonisation in Malian adults. This study will inform the study team whether intranasal inoculation of reconstituted lyophilised Nlac (hereafter, lyoNlac), can result in immunising colonisation of adult Malian volunteers and the optimal dose to achieve this. This dose and methodology will then be used in future studies looking at the duration and immunogenicity of colonisation induced by LyoNlac in Mali.
125 studies on the registry are indexed under Meningitis, Meningococcal; 10 are open to participants now.
This study's enrollment of 55 is below the median of 538 across 113 interventional studies indexed under Meningitis, Meningococcal.
Browse Meningitis, Meningococcal studies →This is the only study on the registry with Center for Vaccine Development - Mali as lead sponsor.
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Inclusion Criteria:
Exclusion Criteria:
Eligibility Minimum Age: 18 Years Maximum Age: 45 Years Sex: All Gender Based: No Accepts Healthy Volunteers: Yes
Criteria: Inclusion Criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Challenge participants will be inoculated intranasally with reconstituted, previously lyophilised Neisseria lactamica (LyoNlac). The initial dose will be 10\^5 colony forming units and will be escalated to a maximum of 10\^7 colony forming units to find the dose which successfully colonises at least 70% of volunteers.
Biological: Intranasal inoculation with Neisseria lactamica
Lyophilised Neisseria lactamica will be reconstituted and administered to participants intranasally.
Establish the impact of nasal inoculation of healthy Malian volunteers with reconstituted lyophilised Neisseria lactamica by assessing nasopharyngeal colonisation with Neisseria species
Throat swabs will be taken at standardised visits and analysed for nasopharyngeal colonisation with Neisseria species. Standard tests include culture and polymerase chain reaction (PCR)
Time frame: 6 months
Establish the effect of the nasal inoculation of healthy Malian volunteers with reconstituted lyophilised Neisseria lactamica by collecting information about symptoms
Information about symptoms will be collected at standardised visits. Any symptoms will be recorded and assessed by a study doctor. If deemed necessary by the study doctor further tests will be requested.
Time frame: 6 months
Analyse the haemoglobin of healthy Malian volunteers inoculated with reconstituted lyophilised Neisseria lactamica
Blood samples will be taken at specified time points and compared to those collected at baseline. Any change in results will be recorded and, if deemed necessary by the medical team, further tests will be requested. Standard tests - haemoglobin - g/dL
Time frame: 3 months
Analyse the white cell count of healthy Malian volunteers inoculated with reconstituted lyophilised Neisseria lactamica
Blood samples will be taken at specified time points and compared to those collected at baseline. Any change in results will be recorded and, if deemed necessary by the medical team, further tests will be requested. Standard tests - white cell count - x 10\^9/L
Time frame: 3 months
Analyse the platelet count of healthy Malian volunteers inoculated with reconstituted lyophilised Neisseria lactamica
Blood samples will be taken at specified time points and compared to those collected at baseline. Any change in results will be recorded and, if deemed necessary by the medical team, further tests will be requested. Standard tests - Platelet count x 10\^9/L
Time frame: 3 months
Analyse the biochemistry blood results (ALT) of healthy Malian volunteers inoculated with reconstituted lyophilised Neisseria lactamica
Blood samples will be taken at specified time points and compared to those collected at baseline. Any change in results will be recorded and, if deemed necessary by the medical team, further tests will be requested. Standard tests - ALT
Time frame: 3 months
Analyse the biochemistry blood results (Creatinine) of healthy Malian volunteers inoculated with reconstituted lyophilised Neisseria lactamica
Blood samples will be taken at specified time points and compared to those collected at baseline. Any change in results will be recorded and, if deemed necessary by the medical team, further tests will be requested. Standard tests - Creatinine (mg/dL)
Time frame: 3 months
The dose of reconstituted lyophilised Neisseria lactamica required for nasopharyngeal colonisation in at least 70% of inoculees
The dose will be confirmed by throat swabs taken from participants and analysed for bacteria by culture and polymerase chain reaction. The desired dose will be confirmed when at least 70%o of inoculees are colonised
Time frame: 6 months
To measure Neisseria lactamica specific immunity following nasal inoculation with reconstituted lyophilised Neisseria lactamica
Blood samples will be collected at standardised visits and antibody levels (mg/dL) will be measured to assess if those colonised with Neisseria lactamica show an increase in antibody levels in comparison to baseline
Time frame: 1 year
Plan to share: No
No publications or documents are linked to this record.
Ran from Mar 2021 to primary completion in Oct 2021, 7 months.
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This study is completed, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.
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