> The reason I'm asking is to understand how the vaccine designers determine if there are any long-term effects of having this artificial material inside your body
The properties of mRNA are well known and have been for decades. Your cells are constantly producing more from the nucleus. It degrades, even more so when it gets transcribed. That's the beauty of this, it's self-limiting.
The only 'artificial' thing about it is the special base that's added to avoid detection by the immune system. Everything else is the exact same compounds present in your cells.
What happens once it degrades? Does it eventually get decomposed into constituent molecules? Or removed from your body somehow? And what happens to that base?
The properties of mRNA are well known and have been for decades. Your cells are constantly producing more from the nucleus. It degrades, even more so when it gets transcribed. That's the beauty of this, it's self-limiting.
The only 'artificial' thing about it is the special base that's added to avoid detection by the immune system. Everything else is the exact same compounds present in your cells.