There actually have been mRNA vaccine trials for more than a decade[0]. The thing about mRNA vaccines is that they have far fewer moving parts, so to speak, than conventional vaccines. So the mRNA vaccine for two different diseases will differ far less than two conventional vaccines for different diseases.
As I understand it, a reasonable comparison is between two mRNA vaccines and two flu vaccines from different years. So if you trust the 10 years of studies that don't show any long term negative effects, and you trust that the particular protein won't have long term ill effects (and, well, if it does, you'd also get them from the virus and probably worse), then the set of assumptions you need to make are relatively small, and essentially the same as the ones you'd make in getting any given flu vaccine.
So please also take the time to educate yourself before calling others "blind"!
As I understand it, a reasonable comparison is between two mRNA vaccines and two flu vaccines from different years. So if you trust the 10 years of studies that don't show any long term negative effects, and you trust that the particular protein won't have long term ill effects (and, well, if it does, you'd also get them from the virus and probably worse), then the set of assumptions you need to make are relatively small, and essentially the same as the ones you'd make in getting any given flu vaccine.
So please also take the time to educate yourself before calling others "blind"!
[0]: https://www.clinicaltrialsarena.com/comment/evolution-mrna-v...