A phase 2, randomized, double-blind, placebo-controlled clinical study of Nexvax2, in adults subjects with confirmed CeD who have been following a gluten free diet for at least 12 consecutive months prior to screening. This study will evaluate efficacy of Nexvax2 administered subcutaneously. The study plan consists of 3 periods: a screening period of 6 weeks, an approximately 16 week treatment period, and a 4 week post-treatment observational follow-up.