Humoral responses to the SARS-CoV-2 spike and receptor binding domain in context of pre-existing immunity confer broad sarbecovirus neutralization.

Since the emergence of SARS-CoV-2 (SARS-2), multiple vaccine candidates were developed and studied both preclinically and clinically. Nearly all are based on the SARS-2 spike glycoprotein or its receptor binding domain (RBD). Studies of these vaccine candidates have largely been in a SARS-2 naïve context. However, pre-existing immunity to SARS-2 acquired through infection or vaccination continues to increase. Evaluating future vaccine candidates in context of this pre-existing immunity is necessary to understand how immune responses are subsequently influenced. Here, we evaluated the serum and IgG+ B cell responses to the SARS-2 RBD in context of pre-existing immunity elicited by the full SARS-2 spike, and we compared this to boosting with the full SARS-2 spike. Boosting with the SARS-2 RBD resulted in increased reactivity to RBD epitopes, but both immunization regimens resulted in similarly broad neutralization across diverse sarbecoviruses. These findings may inform comparison among SARS-2 RBD-based vaccine candidates to currently approved spike-based candidates.

由于SARS-COV-2（SARS-2）的出现，在临床上开发了多个疫苗，并基于SARS-2尖峰糖蛋白或其受体结合域（RBD）的研究（RBD）未来在这种预先存在的免疫复杂的背景下，候选疫苗是为了了解后来的免疫回应如何影响，我们在这里评估了对SARS-2 RBD的血清和IgG+ B细胞的反应。 D表位，但两者都免疫抑制在潜水员SARBecovires中，方案导致了类似的神经化。