Immunogen sequence: GHLPKPTLWA EPGSVIIQGS PVTLRCQGSL QAEEYHLYRE NKSASWVRRI QEPGKNGQFP IPSITWEHAG RYHCQYYSHN HSSEYSDPLE LVVTGAYSKP TLSALPSPVV TSGGNVTLQC VSQVAFDGFI LCKEGEDEHP QRLNSHSHAR GWSWAIFSVG PVSPSRRWSY RCYAYDSNSP YVWSLPSDLL ELLVPGVSKK PSLSVQPGPM VAP