Preexisting vs. de novo antibodies against SARS-CoV-2
in individuals without or with virus infection:
impact on antibody therapy, vaccine research and serological testing
https://transmedcomms.biomedcentral.com/articles/10.1186/s41231-021-00093-2
>individuals may have pre-existing antibodies to
>recently emerged SARS-CoV-2 prior to the outbreak
>due to infections with related common cold coronaviruses,
> :
>such antibodies may prove to be extremely beneficial
>by providing pre-existing protective immunity to the hosts
>when they bind to the conserved neutralizing epitopes
>on the S2 domain of the spike protein.

>>24とも関連するが
SARS-CoV-2感染歴がなくても交差反応を示す抗体を持つ人がいて
それはHCoV感染によるものだろうと
特にS2サブユニットに結合する抗体は防御に役立つ
S2は異なるコロナウイルスでも相同性が保たれ
変異による免疫逃避も生じ難いと考えられる

この点はコロストラム中のBCoV抗体にも当てはまる