The present invention relates to an antibody or antibody fragment capable of binding to phosphorylcholine and/or a phosphorylcholine conjugate, wherein the antibody or antibody fragment comprises a variable heavy chain (VH) domain and/or a variable light chain (VL) domain, and wherein—(a) the VH domain comprises an amino acid sequence that includes one, two or three complementarity determining regions (CDRs) selected from the group consisting of : a CDR1 sequence comprising an amino acid sequence having at least 25%, 50%, 75% or 100% sequence identity to the sequence of SEQ ID NO : 17; a CDR2 sequence comprising an amino acid sequence having at least 5%, 11%, 17%, 23%, 29%, 35%, 47%, 52%, 58%, 64%, 70%, 76%, 82%, 94% or 100% sequence identity to the sequence of SEQ ID NO : 18; and a CDR3 sequence comprising an amino acid sequence having at least 4%, 9%, 13%, 18%, 22%, 27%, 31%, 36%, 40%, 45%, 50%, 54%, 59%, 63%, 68%, 72%, 77%, 81%, 86%, 90%, 95% or 100% sequence identity to the sequence of SEQ ID NO : 19, 20, 21 or 22; and/or (b) the VL domain comprises an amino acid sequence that includes one, two or three complementarity determining regions (CDRs) selected from the group consisting of : a CDR4 sequence comprising an amino acid sequence having at least 5%, 11%, 17%, 23%, 29%, 35%, 47%, 52%, 58%, 64%, 70%, 76%, 82%, 94% or 100% sequence identity to the sequence of SEQ ID NO : 23 or 24; a CDR5 sequence comprising an amino acid sequence having at least 14%, 28%, 42%, 57%, 71%, 85% or 100% sequence identity to the sequence of SEQ ID NO : 25; a CDR6 sequence comprising an amino acid sequence having at least 11%, 22%, 33%, 44%, 55%, 66%, 77%, 88% or 100% sequence identity to the sequence of SEQ ID NO : 26.