Right. It’s probably unnecessary in America for the boosted at this point given that so many of us also had BA.1, BA.2, or will meet their bouncing baby boy. But antibodies are like money. There reaches a point where more antibody is unnecessary.Yeah, the headlines all shout about how after 4 weeks there isn't any better protection against **infection**.
BUT... they all bury the lede: The second booster is still protecting against serious disease (more so than with just one booster) even up to six weeks. And it's only been widely in use for six weeks, so, we don't know when or if the protection against hospitalization will wane.
Still, immunity will wane. And one of the most significant features of mRNA vaccines is their adaptability. By fall, it will be past time for updated vaccines closer to current strains. They manage yearly turnaround for flu and those aren’t mRNA vaccines (yet).