The virologists on TWIV say the media doomsday stuff about the Delta variant is mostly BS. All the talk about R0 ignores the fact that it depends heavily on human behavior. If we all stop wearing mask and go out to bars, whatever variant is going around is going to have a very high R0. They also say there is zero evidence it is more virulent than other variants. When you get vaccinated, you develop a lot of antibodies to that particular variant the vaccine was designed for, but you also develop a much broader T-cell and B-cell immunity to all variants. You will very likely never notice if you get re-infected with the original variant, but those antibodies will fade over several months. Then you depend on T-cell and B-cell immunity that lasts years. You might get something like a cold, but never get seriously ill from any variant. Your "cold" will also give you a bunch of antibodies specifically against the variant you caught!

That's just how the immune system works.

We're flying electric helicopters on Mars yet you can't turn on your clothes dryer in Texas. That's because scientists are in charge of Mars, and Republicans are in charge of Texas.