This research study evaluates the feasibility and tolerability of an investigational intervention and also tries to define the appropriate dose of the investigational intervention to use for further studies. "Investigational" means that the intervention is being studied and that research doctors are trying to find more about it. It also means that the FDA (US Food and Drug Administration) has not approved the Personalized Neoantigen Cancer Vaccine for any use in patients, including people with CLL.