By late 2022 almost everyone had antibodies, and the oldest had the fewest

Once home testing replaced reported testing, **the ability to estimate US
SARS-CoV-2 incidence was hampered** — people stopped being counted. Blood
donations do not depend on anybody reporting anything, so a nationwide
longitudinal donor cohort was used instead.

What changed in fifteen months

Vaccination-alone did not fall because people lost antibodies. It fell because
they were infected as well, and moved into the hybrid column — which went from
under one in ten to nearly half.

The inversion worth noticing

**Hybrid immunity has been reported to provide better protection than
infection or vaccination alone.** So the interesting question is who has it.

**The group with the lowest hybrid immunity is the group with the highest risk
of severe disease if infected.**

Which is not a failure

The report's own reading of that gap is the part most easily misread:

**Low prevalence of infection-induced and hybrid immunity among older adults
reflects the success of public health infection prevention efforts.**

Older adults have less infection-derived immunity **because fewer of them were
infected** — shielding, earlier vaccination, more caution. The prevention
worked. The consequence is that their protection rests more on vaccination and
less on infection, which is why the conclusion is not "they are fine" but the
opposite: **older adults should stay up to date with recommended COVID-19
vaccination, including at least one bivalent dose.**

Source: Centers for Disease Control and Prevention, MMWR.