As promised, I'll try to explain why it's not possible that being vaccinated with a vaccine approved in the US** will give you a positive PCR test for Covid.   I can't find something not behind a paywall that explains it as clearly as I like, so I'm going to have to piece it together.    First, the PCR test for Covid.  Here's a decent explanation of how PCR works: https://www.genome.gov/es/node/83066 The first thing that is not well explained: -RNA is very unst