To investigate whether any variation in the levels of IgG antibody responses to the blood stage malaria antigens were either due to CTX prophylaxis or in utero HIV exposure, IgG antibody responses to Salmonella Typhimurium lipopolysaccharide (STM LPS) a common infection in childhood particularly in this region [35,45–47], and EPI vaccine induced responses to Bordetella pertussis toxin (PT) were measured in HEU children and compared with HUU children. Here, F2 is linked to infection.