Also, in a phase 2a RTS,S/AS malaria vaccine study in malaria-naïve volunteers, there was a strong association between the titers of CSP-specific antibodies and the frequency of CSP peptide-reactive CD4+ T cells in the same individual, and the frequencies of CD4+ T cells secreting either or both IL-2 and TNF-α (but not IFN-γ) were higher in protected than non-protected subjects44. This evidence concerns the gene CD4 and malaria.