Sourced of - Dr John Campbell - https://www.youtube.com/watch?v=DO1Ivk6JYyE Two different manafacturing processes. Pfizer covid vaccines for the clinical trials were mostly produced using manufacturing ‘process 1’ whereas the vaccines used for population vaccination were produced using a different ‘process 2’ Interview with Josh Guetzkow PhD Here is the BMJ link: bmj.com/content/378/bmj.o1731/rr-2 Covid-19: Researchers face wait for patient level data from Pfizer and Moderna vaccine trials Josh's handle on X.com is @joshg99 and here is a link to a thread I did on P1 vs. P2: twitter.com/joshg99/status/1658421192326365185 Here is a link to my blog: researchrebel.substack.com nejm.org/doi/suppl/10.1056/NEJMoa2034577/suppl_file/nejmoa2034577_protocol.pdf phmpt.org/wp-content/uploads/2023/04/125742_S1_M5_5351_c4591001-interim-mth6-report-body.pdf