a) the scenario when the foreign material is immediately degraded by enzymes or other mechanism, before actually accomplishing anything,
b) the scenario when the foreign material causes massive immune reaction in form of inflammation, potentially killing the host.
AFAIK navigating between those two extremes took decades during development of RNA vaccines. But now it seems that we can avoid both.
a) the scenario when the foreign material is immediately degraded by enzymes or other mechanism, before actually accomplishing anything,
b) the scenario when the foreign material causes massive immune reaction in form of inflammation, potentially killing the host.
AFAIK navigating between those two extremes took decades during development of RNA vaccines. But now it seems that we can avoid both.