The present invention provides conjugates of peptide derivatives of the mammalian peptide hormones angiotensinogen, angiotensin I and angiotensin II, presented in a repetitive scaffold by coupling the peptide derivatives to a carrier, particularly a virus-like particle (VLP). The invention also provides methods of producing such conjugates, and immunotherapeutic uses of the resulting immunogen conjugates for the therapy and prophylaxis of conditions associated with the renin-activated angiotensin system.