Immunogen sequence: TENIKHQPGG GRAKVEKKTE AAATTRKPES NAVTKTAGPI ASAQKQPAGK VQIVSKKVSY SHIQSKCGSK DNIKHVPGGG NVQIQNKKVD ISKVSSKCGS KANIKHKPGG GDVKIESQKL NFKEKAQAKV GSLDNVGHLP AGGAVKTEGG GSEAPLCPGP PAGEEPAISE AAPEAGAPTS ASGLNGHPTL SGGGDQREAQ TLDSQIQETS I;