Experimental Pneumococcal Carriage in People Living With HIV

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.