Provided is a polypeptide composition comprising one or more polypeptides, which polypeptides are immunogenic in a vertebrate such that they cause the vertebrate to produce immune system cells capable of recognising at least one epitope from an arthropod saliva protein fraction, wherein the arthropod saliva protein fraction has a mass of 40kDA or less, and wherein the polypeptides are selected independently from: the polypeptide sequences of SEQ ID NO: 1-44 or sub-sequences from these sequences, the sub-sequences having 7 amino acids or more； or from polypeptide sequences having 85% homology or more with one or more of the above sequences and contained in one or more of the following databases: GenBank, Protein Data Bank (PDB), SwissProt, Protein Information Resource (PIR), Protein Research Foundation (PRF), or CDS translations of these.本發明提供含一或多種多肽之多肽組成物，該等多肽類在脊椎動物體內可產生免疫性，因此其可致使該脊椎動物產生能自節肢動物唾液蛋白質部份辨識至少一種抗原決定位之免疫系統細胞，其中該節肢動物唾液蛋白質部份具有40kDA或更小之質量，且其中該等多肽類係獨立選自：具有SEQ ID NO：(序列辨識編號)1-44或得自這些序列的亞序列之多肽序列，該等亞序列具有7或更多個胺基酸；或選自與上述序列中之一或多種具85%或更高同源性且包含在以下資料庫中之一或多種的多肽序列：GenBank、Protein Data Bank(PDB)、SwissProt、Protein Information Resource(PIR)、Protein Research Foundation(PRF)或彼等之CDS轉譯物。
