no, these are the very first vaccines to use mrna technology successfully. same with the vaccine delivery technology -- lipid nanoparticles.
that's why there is a lot of concern about their potential long-term side effects. in animal models, one of moderna's older vaccines (not for covid) was found to cause severe liver damage... likely as a result of the nanoparticle formulation they were using, rather than the mrna itself, but who knows.
personally, given the data that i've seen so far, i'd be more comfortable with taking the pfizer mrna vaccine than the moderna one. especialy when you add in moderna's reputation for peak sleaziness and non-transparency, it seems especially risky to be one of their guinea pigs in the general population.
that's why there is a lot of concern about their potential long-term side effects. in animal models, one of moderna's older vaccines (not for covid) was found to cause severe liver damage... likely as a result of the nanoparticle formulation they were using, rather than the mrna itself, but who knows.
personally, given the data that i've seen so far, i'd be more comfortable with taking the pfizer mrna vaccine than the moderna one. especialy when you add in moderna's reputation for peak sleaziness and non-transparency, it seems especially risky to be one of their guinea pigs in the general population.