>>11451705We have already created vaccines for viruses for which it can be done easily.
Something like smallpox is extremely easy - the disease naturally induces lifelong immunity, so all you need to do is to trigger the immunity without getting the disease. You can do that wit the scabs of the infected in the worst case.
But some viruses are mor complicated. They don't result in lifelong immunity, or in some cases the subsequent infections are even worse than the first one. There is no easy way to make a vaccine against those.
