CD4 and influenza: Nevertheless, in a vaccination setting of individuals receiving a split vaccine, a subset (ICOS+CXCR3+CXCR5+) of circulating influenza-specific CD4+ T follicular helper (TFH) cells correlated with more effective B-cell responses and greater Ab titres, suggesting that eliciting this type of cells could be important in inducing more effective Ab-based vaccines (Bentebibel et al., 2013).