A SARS-CoV-2 vaccine on an NIR-II/SWIR emitting nanoparticle platform

• DOI: 10.1126/sciadv.adp5539
• Publication Date: 2025-02-07T18:58:26Z
• Authors: Yingying Jiang; Mrinmoy Sanyal; Noor A. Hussein; Ani Baghdasaryan; Mengzhen Zhang; Feifei Wang; Fuqiang Ren; Jiachen Li; Guanzhou Zhu; Yifan Meng; Julia Zofia Adamska; Elizabeth Mellins; Hongjie Dai
• Keywords: 2019-20 coronavirus outbreak

The COVID-19 pandemic caused a global health crisis that resulted in millions of deaths. Effective vaccines have played central roles curtailing the pandemic. Here, we developed down-converting near-infrared IIb (NIR-IIb; 1500 to 1700 nanometers) luminescent, pure NaErF4@NaYF4 rare-earth nanoparticle (pEr) as vaccine carriers. pEr nanoparticles were coated with three layers cross-linked biocompatible polymers (pEr-P3; ~55 and conjugated receptor binding domain (RBD) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. Upon subcutaneous injection pEr-P3-RBD nanovaccine mice, vivo NIR-IIb imaging revealed active trafficking migration lymph nodes through lymphatic vessels. Two doses adjuvant-free elicited long-lasting (>7 months) high titers serum viral neutralization antibody anti-RBD immunoglobulin G, along robust RBD-specific germinal center B cells T follicular helper cells. We devised NIR-II molecular nodes, opening noninvasive assessments vaccine-elicited immune responses longitudinally.