If you add to the equation all the trials on DC vaccine therapy conducted by Mayo Clinic, then everything makes sense. Merck didn't build these vaccine manufacturing facilities for short term. Note that Building 63A is for pre-filled syringe of pneumococcal vaccine. WP50 has other immune boosters as elaborated in Dr. Caravello's analysis.
Dendritic Cell Therapy, Cryosurgery, and Pembrolizumab in Treating Patients With Non-Hodgkin Lymphoma Phase I/II Study of Dendritic Cell Therapy Delivered Intratumorally After Cryoablation and Anti-PD-1 Antibody (Pembrolizumab) for Patients With Non-Hodgkin Lymphoma