Thanks for the source. While I did not read the whole document, and correct me if I am wrong, it seems that vaccines manufactured from both Process 1 and 2 are administered to the trial participants though.

Here's a section snippet: "The initial BNT162b2 was manufactured using “Process 1”; however, “Process 2” was developed to support an increased scale of manufacture. In the study, each lot of “Process 2”-manufactured BNT162b2 will be administered to approximately 250 participants 16 to 55 years of age. The safety and immunogenicity of prophylactic BNT162b2 in individuals 16 to 55 years of age vaccinated with “Process 1” and each lot of “Process 2” study intervention will be described."