Abstract: The present invention relates to a fragment of apolipoprotein B, for immunization for prophylactic or therapeutic treatment of mammals, including humans, against ischemic cardiovascular diseases, in particular myocardial infarction or stroke, as well as diagnosing the presence or absence of antibodies related to increased or decreased risk of developing ischemic cardiovascular diseases including stroke, using said peptide in an assay, pharmaceutical compositions comprising the peptide. The invention further encompasses a particular peptide sequence aggravating disease, which sequence then can be used for diagnostic assays.