The goal of this experimental pneumococcal carriage study is to to characterise rates and determinants of experimental pneumococcal carriage in PLHIV. The main questions it aims to answer are: * can PLHIV be experimentally inoculated with pneumococcus in a safe manner? * what are the immunological determinants of pneumococcal carriage in PLHIV compared to HIV-negative participants? * how do the pneumococcal carriage dynamics differ between PLHIV and HIV-negative participants? Participants will be inoculated intranasally with a controlled concentration of pneumococcus after which they will be monitored for 21 days during which nasal and systemic immune dynamics and pneumococcal carriage dynamics will be evaluated. At the end of the study any participants exhibiting carriage will have the pneumococcus cleared with antibiotics.
The EHPC has been established at the Malawi-Liverpool Wellcome centre (MLW) and demonstrated acceptability and feasibility in this setting. To date, over 250 participants have been enrolled on the EHPC at MLW without any study complications. Participants will be inoculated in both nostrils with a controlled concentration of penicillin-sensitive Streptococcus pneumoniae. Participants will be followed up for 25 days following inoculation during which sampling will occur at established time-points to establish pneumococcal carriage and immune cell/immunoglobulin dynamics. After 21 days, participants who demonstrate pneumococcal carriage will commence an antibiotic course to clear the bacteria (participants may be advised by the clinical study team to commence antibiotics earlier if they develop any symptoms of pneumococcal disease). Participants will remain under close observation in study accommodation for the first 3 days following inoculation, and will then be monitored daily at home via text message and telephone calls. A final health-check and exit interview will be conducted on day 25 to evaluate participant satisfaction with study participation. The overall objective is to characterise rates and determinants of experimental pneumococcal carriage in PLHIV in Blantyre, Malawi in order to inform vaccine evaluations and vaccine policy.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
PREVENTION
Masking
NONE
Enrollment
150
A controlled concentration of streptococcus pneumoniae serotype 6B is placed in both nares of participants
Malawi-Liverpool Wellcome City
Blantyre, Malawi
Proportion of participants with pneumococcal carriage in the nasopharynx post-inoculation
Measured by classic culture and PCR-based methods
Time frame: From inoculation up to 21 days post-inoculation
Average pneumococcal carriage density in the nasopharynx post-inoculation
Measured by classic culture and PCR-based methods
Time frame: From inoculation up to 21 days post-inoculation
Nasal immunoglobulin concentration at baseline
Measured in nasal fluid
Time frame: Baseline
Change in nasal immunoglobulin concentration following inoculation
Measured in nasal fluid
Time frame: Baseline to 21 days post-inoculation
Density of immune cells in the nasal mucosa at baseline
Immune cell to epithelial cell ratio measured in nasal mucosal cell samples
Time frame: Baseline
Change in density of immune cells in the nasal mucosa following inoculation
Immune cell to epithelial cell ratio measured in nasal mucosal cell samples
Time frame: Baseline up to 21 days post-inoculation
Immune cell activation activation in the nasal mucosa at baseline
Concentration of markers of immune cell activation measured in nasal fluid and cell samples
Time frame: Baseline
Change in immune cell activation in the nasal mucosa following inoculation
Concentration of markers of immune cell activation measured in nasal fluid and cell samples
Time frame: Baseline up to 21 days post-inoculation
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