> - delivery mechanism: you need to take a very unstable molecule, protect it from the environment - both external, and when inside the patient - and insert it into a human cell. (This is called the "platform", and is usually developed independently from the specific payload.)
The most amazing thing is that now that the platform is proven secure in dozens of millions of people, it should be be very easy and fast to get approval for other payloads. Biontech for example wants to go after cancers - a platform that can deliver payloads targeted to an individual's cancer is nothing short of a game changer in cancer treatment because the current standard of blasting the patient's body with a lot of highly toxic chemicals is arcane compared to letting the body's immune system do the cleanup.
Even if the platform is safe, the payload itself needs to have its safety proven. Remember, the payload is just instructions, and those instructions make your cells pump out oodles of arbitrary proteins. That in itself can cause health problems. see e.g. the AstraZeneca vaccine's safety issues, which were caused IIUC by immune responses to the manufactured proteins. DNA vaccine, not mRNA, but the principle is the same.
re: cancers, that is actually what this technology was originally developed for! Moderna has been spending about a decade getting this tested and proven out for the cancer role, and they're quite close. From my quick reading of the literature, there seems to be some regulatory confusion about how exactly to run approval for this kind of personalized drug design (testing the method of generating the individual drugs?), but the bar is usually much lower for cancers with high mortality rates.
The most amazing thing is that now that the platform is proven secure in dozens of millions of people, it should be be very easy and fast to get approval for other payloads. Biontech for example wants to go after cancers - a platform that can deliver payloads targeted to an individual's cancer is nothing short of a game changer in cancer treatment because the current standard of blasting the patient's body with a lot of highly toxic chemicals is arcane compared to letting the body's immune system do the cleanup.