<p><b>Copyright information:</b></p><p>Taken from "Ovine Enzootic Abortion (OEA): a comparison of antibody responses in vaccinated and naturally-infected swiss sheep over a two year period"</p><p>http://www.biomedcentral.com/1746-6148/3/24</p><p>BMC Veterinary Research 2007;3():24-24.</p><p>Published online 28 Sep 2007</p><p>PMCID:PMC2042495.</p><p></p