RecruitingPhase 1Biological interventionA Study of RNA-lipid Particle (RNA-LP) Vaccines for Newly Diagnosed Pediatric High-Grade Gliomas (pHGG) and Adult Glioblastoma (GBM)The primary objective will be to demonstrate the manufacturing feasibility and safety, and to determine the maximum tolerated dose (MTD) of RNA-LP vaccines in (Stratum 1) adult patients with newly diagnosed GBM (MGMT low level or unmethylated in adults only) and (Stratum 2) in pediatric patients with newly diagnosed HGG (pHGG). Funding Source - FDA OOPD