After adjusting for age and Hb type, only an IgG response to the Cambodian parasite isolate CP803 correlated with protection against malaria (OR= 0.28, 95% CI 0.10-0.75, p=0.011); however, this IgG response did not correlate with a longer time to first malaria episode (Table 5). This evidence concerns the gene GSTM1 and malaria.