Immunogen sequence: KGFRENFESM YTSVDTSIPS PPGPNCQFLG GDHYSPLLPN QYPVPSRFYP DLPGQAKDVV PQAYWLGAPR DHSYEAEFRA VSMKPAFLPS APGPTMSYYR GQEVLAPGAG WPVAPQYPPK MGPASWFRPM RTLPMEPGPG GSEGRGPEDQ GPPLVWTEIA PIRPESSDSG LGEGDSKRRR VSPYPSSGDS SSPAGAPSPF DKEAEGQFYN YFP