That title is very misleading, the paper at https://www.medrxiv.org/... definitely does _not_ say that it affects the vaccinated more than the unvaccinated. Specifically the comment "No statistically significant difference was observed in the rates of B.1.1.7 infection in FE cases versus unvaccinated controls".

The study was attempting to determine whether the time between doses (up to 7 weeks after the 2nd dose) had an impact on infection rates...and it hasn't even gone through peer review, yet....

For some context, the Pfizer vaccine, which is based on using mRNA to train your antibodies to identify a specific part of the spike protein, was the initial vaccine which had the logistical issue of needing to be stored at a low temperature. The B.1.351 strain also retains 1% of the current infected within their sample size in Israel.

The paper also notes "From a biological point of view, the breakthrough cases observed in this study might either be due to immune evasion of both strains, or the ability of B.1.17 to create higher viral loads[3]", but they also noted that they didn't measure the white blood cell responses, only antibody abilty to identify the knife-like spike protein.

So these two mutations developed tech where B.1.1.7 mutated its spike protein to make it less identifiable by our immune response https://en.wikipedia.org..., and B.1.351 has higher rate of reproduction due to its refinement of its spike proteins at https://en.wikipedia.org....

As vaccines are typically intended to train your immune response system, E484K is what will really fuck us...