Immunogen sequence: MAETLPGSGD SGPGTASLGP GVAETGTRRL SELRVIDLRA ELKKRNLDTG GNKSVLMERL KKAVKEEGQD PDEIGIELEA TSKKSAKRCV KGLKMEEEGT EDNGLEDDSR DGQEDMEASL ENLQNMGMMD MSVLDETEVA NSSAPDFGED GTDGLLDSFC DSKEYVAAQL RQLPAQPPEH AVDGEGFKNT LETSSLNFKV TPDIEESLLE PEN