ワクチン接種者はοに感染することでδバリアントに対する中和抗体の機能がο株以上に強化される

日本よりもワクチン接種率の高いデンマークでδ株感染者数が激減した理由か？
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Delta virus neutralization was enhanced 6.6-fold in vaccinated but only 2.5-fold in unvaccinated participants.
Moreover, vaccinated participants were able to mount a stronger neutralization response against Delta
relative to Omicron virus.

"Omicron infection of vaccinated individuals enhances neutralizing immunity against the Delta variant"
https://secureservercdn.net/166.62.108.196/1mx.c5c.myftpupload.com/wp-content/uploads/2022/01/MEDRXIV-2021-268439v2-Sigal.pdf