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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
55
Lyophilised Neisseria lactamica will be reconstituted and administered to participants intranasally.
CVD Mali
Bamako, Mali
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
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