title: Meningococcal vaccines: results of prospective double blind trials usage in population at risk on Gold Fields Mines.
mesh_terms: D001428:Bacterial Vaccines; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D006046:Gold; D006801:Humans; D008585:Meningitis, Meningococcal / Q000517:prevention & control*; D008906:Mining; D009345:Neisseria meningitidis / Q000276:immunology*; D010919:Placebos; D013019:South Africa
chemical_list: D001428:Bacterial Vaccines; D010919:Placebos; D006046:Gold