Pancreatic Cancer Vaccine Triggers Immune Response Before Tumors Develop
(www.insideprecisionmedicine.com)
I think the purpose of giving it to people who are at high risk of the cancer make the auto-immune risks later a thing they will at least be alive to run into later; and maybe a fix for that will be found in time.
Given the current result of getting the cancer is very likely death, trading that for a potential of death after years more life seems to be a no-brainer, this FUD-like statement notwithstanding.