Immunogen sequence: MRHSLTKLLA ASGSNSPTRS ESPEPAATCS LPSDLTRAAA GEEETAAAGS PGRKQQFGDE GELEAGRGSR GGVAVRAPSP EEMEEEAIAS LPGEETEDMD FLSGLELADL LDPRQPDWHL DPGLSSPGPL SSSGGGSDSG GLWRGDDDDE AAAAEMQRFS DLLQRLLNGI GGCSSSSDSG SAEKRRRKSP GGGGGGGSGN DNNQAATKSP RKA