The purpose of the core is to provide HLA typing for class I and class II alleles for all projects. The typing will be performed in the Immunogenetics Laboratory of Georgetown University Medical School. Five hundred individuals will be HLA type over the five year period. Standard microcytoxicity will be used to determine class I specificities using locally prepared typing trays specially designed to identify HLA specificities in individuals of African ancestry. A polymerase chain reaction based DNA typing method, Sequence Specific Primers (PCR-SSP), will be used to determine class II alleles. The technology will be transferred to Cameroon during the fourth year through a training workshop. We will correlate immune responses to defined P. falciparum vaccine candidate antigens with HLA type to determine whether HLA affects the specificity and/or rate of development of protective immunity. A Cameroonian collaborator will travel to the US during year one to learn how to collect and preserve samples for HLA typing. In year three, core personnel will travel to Cameroon to consult with researchers and help prepare for the training workshop to be held in year 4.