def get_antigen_name(qseqid):
    """
    Get the antigen name from the BLASTN result query ID.
    The last item delimited by | characters is the antigen name for all
    antigens (H1, H2, serogroup)

    @type qseqid: str
    @param qseqid: BLASTN result query ID
    @return: antigen name
    """
    if qseqid:
        return qseqid.split('|')[-1]