On the one end, a combination of DNA vaccines with EP in a homologous prime-boost approach could generate antibody responses comparable to those that are induced by protein in Complete Freund Adjuvant, and also amplified CTL responses [46] . EP may provide a prime-boost combination equivalent to that observed using viral vectors, and it is now undergoing testing in the clinic using a DNA vaccine for patients with prostate cancer. Repeated EP has been accepted by patients without the need for general or local anaesthesia and with no apparent long-term ill effects [47] .