The present study would provide information for vaccine im provement. As described in Section 1.2, PolyPEPI1018 consists of the 7 most frequently expressed CTAs in CRC, and there is a 95% probability the 3 of these 7 CTAs are expressed in any CRC cell . It is expected that PolyPEPI 1018 will induce cytotoxic T cell responses against CTAs expressed in CRC cells, thereby matching the vaccines to patient’s tumor antigens and whole HLA genotype. Only a saliva sample, not the traditionally required tumor biopsy, will be required for performing the PEPI Test for the identification of likely responders, thus simplifying and accelerating the selection procedure. Treos Bio ZRT OBERTO -101 Amendment 3 Product: PolyPEPI 1018 Colorectal Cancer Vaccine Page 27 of 81 CONFIDENTIAL In order to examine whether the PEPI Test can predict immune respon ses and identify potential responders (thus providing the basis and the rationale for its use as CDx in future studies) it is essential that the present study allows 12 weeks of follow -up after each vaccination . This will also provide useful information to inform us on scheduling (how often vaccination should be repeated) during future multiple-vaccination studies. As described in Section 1.2.2.1, based on the safety profile of similar vaccines, PolyPEPI 1018 is expected to be safe and well -tolerated. Side effects are typically mild (Section 1.2.2.1.). Local erythema and edema in the site of vaccination are expected , as well as a flu-like syndrome with minor fever and fatigue. Vaccines, like any other medication that affects the immune system, c an cause adverse effects that may prove life threatening. For example, severe hypersensitivity (allergic) reactions to specific vaccine ingredients have occurred following vaccination; however, such severe reactions are very rare ( Yoshida 2011).