The response was primarily by Th cells, not the TC cells, so yes, this isn't immunity, but it would speed to body's adaptive immune system response.
OTOH, the killer feature of Covid-19 seems to be triggering an out-of-control adaptive immune response. That's probably why kids aren't dying, as their adaptive immune response is still developing.
OTOH, the killer feature of Covid-19 seems to be triggering an out-of-control adaptive immune response. That's probably why kids aren't dying, as their adaptive immune response is still developing.