If the mRNA vaccine is so great and simple, why can't they be used to treat all viruses? Since all viruses contain some kind of a surface antigen, and their genomes are known, and the mRNA technology has been known for at least 20 years, why hasn't that been done not even in some kind of phase 1 trials? Also if all we need is a surface antigen, then why do we worry about virus mutations? What mutates is inside the virion, but the surface protein is just a protein that binds to a specific receptor for a specific virus, so it can't possibly mutate, right? Why don't have an mRNA flu vaccine? Or better yet a single mRNA based flu vaccine that would work against all strains of flu? Just encode for the flu's surface antigen and let our cells generate the flu specific spikes and train our immune system to recognize them. Something doesn't add up here.