Experimental Pneumococcal Carriage in People Living With HIV

Inclusion Criteria: * Aged 25 to 45 years old * Fluent spoken and written Chichewa or English * Able to give informed written consent * Access to a functional mobile phone * Establish on antiretroviral therapy for ≥2 years (if PLHIV) * Viral load below the lower limit of detection (\<LDL) at screening (if PLHIV) * CD4 count over 350 cells/mm³ at screening (if PLHIV) Exclusion Criteria: * HIV-associated hospitalisation and/or treatment for major illness in preceding 2 years * Currently under investigation for HIV-associated weight-loss, chronic diarrhoea, chronic cough, or another unexplained symptom * Previous illness caused by pneumococcus * Additional condition or medication impairing immune response or increasing risk of pneumococcal disease * Living in close contact with an individual vulnerable to pneumococcal disease * Allergy to penicillin * Acute illness in 7 days preceding inoculation * Antibiotic course in last 2 weeks (excluding prophylactic co-trimoxazole in PLHIV) * Pregnant or trying to conceive * Involved in another clinical study (unless observational or in follow-up) * Current regular cigarette smoking (5+ cigarettes per week) * Natural carrier of pneumococcus serotype 6B at screening visit * Participants without a guardian