FDA statement on following the authorized dosing schedules for Covid-19 vaccines
How did they originally decide to do 2 doses, instead of 1 or 3?  How did they originally decide to do 21 days, instead of 42 or 3?<p>Presumably these choices weren&#x27;t picked out of thin air, or made up by some businessperson based on business considerations -- &quot;We think we can get paid twice if we put it in two doses, but if we try to go to three doses it&#x27;ll be impossible to market&quot; -- hopefully that&#x27;s <i>not</i> what happened.<p>Hopefully instead this decision was made based on actual data -- for example in animals or a small group in Phase I or for some similar vaccine, they did actually try N-day dose separations for all 1 &lt; N &lt; 50 and then made some actual measurements of how fast white blood cells attacked the COVID virus in a lab dish or whatever.  The lab test maybe wouldn&#x27;t be as ironclad as the Phase 2 which actually sends the subjects back into the wild and sees how many got COVID in the next 3 months, but it&#x27;s some concrete data.<p>Where is that data?  Couldn&#x27;t you use whatever data was used to decide on the dosing schedule in the first place to quantifiably answer how much worse were the alternative dosing schedules that weren&#x27;t chosen?