The yearly flu vaccines are similar though, and the long term protection against specific variants of CoViD-19 are also similarly lacking because the only ethic

The yearly flu vaccines are similar though, and the long term protection against specific variants of CoViD-19 are also similarly lacking because the only ethical environment to gather test data in now has different, more virilant, variants. It's sort of like a riot shield's effectiveness against metal pipe club weapons, then mining picks, and now axes, all used by a mob. There is still some protection, and it is usually non-harmful to the protected, but the effectiveness is in question and annual training seems to help.