Yunlong Richard Cao
SARS-CoV-2 saltation variant PJ.2.1 has raised concerns over another JN.1-like event. Here we found: 1. PJ.2.1 shows markedly higher ACE2 binding. 2. PJ.2.1's antigenicity remains comparable to the JN.1 family. 3. No increased immune evasion against human plasma. While PJ.2.1 currently lacks the immune evasion capabilities of other contemporary strains (XFG, PQ.16.1.1, BA.3.2.2...), its robust baseline receptor-binding strength mirrors the early evolutionary trajectory of BA.2.86 to JN.1, necessitating continued genomic, epidemiological, and virological surveillance of the PJ.2.1 lineage. Details can be found in the recent BioRxiv manuscript: https://www.biorxiv.org/content/10.64898/2026.09.03.749172v1
