Quantifying absolute neutralization titers against SARS-CoV-2 by a standardized virus neutralization assay allows for cross-cohort comparisons of COVID-19 sera

• DOI: 10.1101/2020.08.13.20157222
• Publication Date: 2020-08-15T14:35:20Z
• Authors: Kasopefoluwa Y. O...; Christian S. Stevens; Chuan-Tien Hung; Satoshi Ikegame; Joshua A. Acklin; Shreyas S. Kowdle; Jillian C. Carmic...; Hsin-Ping Chiu; Kristopher D. Azarm; Griffin D. Haas; Fatima Amanat; Jéromine Klingler; Ian Baine; Suzanne Arinsburg; Juan C. Bandres; Mohammed N.A. Sid...; Robert M. Schilke; Matthew D. Woolard; Hongbo Zhang; ; Andrew J. Duty; Thomas A. Kraus; Thomas M. Moran; Domenico Tortorella; Jean K. Lim; Andrea V. Gamarnik; Catarina E. Hioe; Susan Zolla-Pazner; Stanimir S. Ivanov; Jeremy P. Kamil; Florian Krammer; Benhur Lee
• Keywords: Pandemic; Antibody titer

The global COVID-19 pandemic has mobilized efforts to develop vaccines and antibody-based therapeutics, including convalescent plasma therapy, that inhibit viral entry by inducing or transferring neutralizing antibodies (nAbs) against the SARS-CoV-2 spike glycoprotein (CoV2-S). However, rigorous efficacy testing requires extensive screening with live virus under onerous BSL3 conditions which limits high throughput of patient vaccine sera. Myriad BSL-2 compatible surrogate neutralization assays (VNAs) have been developed overcome this barrier. Yet, there is marked variability between VNAs how their results are presented, making inter-group comparisons difficult. To address these limitations, we a standardized VNA using VSVΔG-based CoV-2-S pseudotyped particles (CoV2pp) can be robustly produced at scale generate accurate titers within 18 hours post-infection. Our CoV2pp showed strong positive correlation CoV2-S ELISA neutralizations in confirmed Three independent groups subsequently validated our (n>120). data show absolute (abs) IC50, IC80, IC90 values legitimately compared across diverse cohorts, highlight substantial but consistent potency support use absIC80 as more meaningful metric for assessing Lastly, used screen identify ultra-permissive 293T clones stably express ACE2 ACE2+TMPRSS2. When combination CoV2pp, now produce sufficient 150,000 VNA/week.