Thank you for posting that. When mRNA shots for COVID were proposed/announced, I went back and found an article I remembered reading about Moderna and mRNA - "Lavishly funded Moderna hits safety problems in bold bid to revolutionize medicine" (circa 2017). A couple of lines from the article stand out "But mRNA is a tricky technology. Several major pharmaceutical companies have tried and abandoned the idea, struggling to get mRNA into cells without triggering nasty side effects". It also discusses the danger of repeated doses of mRNA used in its gene therapy treatment, which is why Moderna changed its focus to vaccines to avoid the repeated dosage problem (as you may recall, before being redefined, "vaccine" used to mean a single shot to provide immunity, so no repeated doses). When the mRNA vaccines were rolled out, I looked for articles or information as to how the pharmaceutical companies had addressed and resolved those known problems, but I have yet to find any explanation.