The trial aimed to prospectively assess the correlates of infection risk and explore potential cross-clade immune responses induced in South African individuals when using the RV144 regimen, which includes clade B and E inserts, in a region dominated by clade C. Responses were compared to those elicited in RV144 and included the overall response rates of plasma IgG and Env-specific CD4+ T cells expressing IFNg and/or IL-2. Here, ERVW-1 is linked to infection.