Clarifying last tweet:

Details of the Hong Kong reinfection show that worry about risk to *the reinfected individual* is misplaced, but they *can* go on to infect *others*, showing that current theories of natural herd immunity are flawed.

Also everyone follow @VirusesImmunity. https://twitter.com/virusesimmunity/status/1297890418168860674

But on the original point:

Headlines on this have said it "shows that some people will not have long-lasting immunity", and "undermines the ability of a vaccine to protect the population"

Dr Iwasaki demonstrates that this is not the case https://twitter.com/VirusesImmunity/status/1297890434262474758

For reference: that chart on primary and secondary immune responses from natural infection is pretty much the spitting image of this one on how vaccines and boosters work https://www.researchgate.net/figure/The-immune-response-following-primary-vaccination-and-natural-infection-booster_fig1_265358601