From December 2020 to June 2021, 1654487 blood donors were tested for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S1 protein, and 1028547 (62.17%) were reactive. A rapid increase in prevalence was due to vaccination. Among a subset of 1567446 donors, 729771 (46.56%) reported SARS-CoV-2 vaccination, of whom 633769 (86.84%) were S1-antibody reactive only in response to vaccination and 68269 (9.35%) were reactive to both S1 and nucleocapsid in response to prior infection; the remainder were not reactive to either antibody. Among the 837675 (53.44%) donors who did not report vaccination, 210022 (25.07%) had reactivity to both antibodies and 29446 (3.52%) to S1 only.

中文翻译：

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160 万献血者中对严重急性呼吸综合征冠状病毒 2 的抗体反应模式：疫苗接种的影响，美国，2020 年 12 月至 2021 年 6 月

2020年12月至2021年6月，1654487名献血者接受了严重急性呼吸综合征冠状病毒2（SARS-CoV-2）S1蛋白抗体检测，1028547名（62.17%）有反应。流行率的迅速增加是由于接种疫苗。在 1567446 名捐献者的一个子集中，729771 名（46.56%）报告了 SARS-CoV-2 疫苗接种，其中 633769 名（86.84%）仅对疫苗接种产生 S1 抗体反应，68269 名（9.35%）对 S1 和核衣壳均有反应应对先前的感染；其余的对任何一种抗体都没有反应。在未报告接种疫苗的 837675 名（53.44%）供体中，210022 名（25.07%）对两种抗体都有反应，29446 名（3.52%）仅对 S1 有反应。