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I got the first dose of the Pfizer-BioNTech vaccine yesterday. I asked the nurse charting my vaccine if they plan to give people the prime and the boost in the same or opposite arm and she simply answered “it doesn’t matter”. I disagree, I think it does matter! Thread
If you give the boost in the same arm as the prime you will be delivering more antigen to an ongoing germinal center reaction, bolstering that reaction to drive out high affinity B cell clones, albeit likely fewer B cell clones.
If you give the boost to the opposite arm, you will be driving a de novo germinal center response in the draining lymph node there. That means more naive B cell recruitment, and more potentially affinity-matured B cells (and secreted antibody!). This is where I am leaning.
Is two “okay” sites of germinal centers and more naive B cell recruitment better or do you need the boost to the same germinal center to drive the best antibody response? This is a quality over quantity question. Which is more protective against SARS-CoV-2?
I think now is the opportune time to do these studies for people with fine needle aspirate protocols! I also signed up for the http://vsafe.cdc.gov and I plan on recording with the CDC which arm I got the vaccine in. Hopefully they will use that data!
