HIV-infected children progress more rapidly to AIDS than adults and, in sub-Saharan Africa, without antiretroviral therapy (ART), more than 50% will die before their second birthday. However, a minority of perinatally infected children will become paediatric non-progressors (PNP). The reasons for this rapid disease progression and the immunological correlates of protection against rapid progression are incompletely understood. This thesis focuses principally on paediatric HIV in...