> Not really. mRNA starts to degrade within minutes of injection, and lasts maybe at most a few days in your body. According to the data I've seen on kinetics

> Not really. mRNA starts to degrade within minutes of injection, and lasts maybe at most a few days in your body. According to the data I've seen on kinetics (these vaccines have been in development since 20 years ago, so there's plenty of basic and animal test data) there's production of the antigen at the site of injection for approximately ten days. There's some systemic production in the liver for 2-4 days, but that's it. The mRNA can last this long (normally, as you correctly say, it would get broken up in minutes) due to the lipid nanoparticles it is bound to, which are the "secret sauce" of this vaccine.