Rasulova, M. | bioRxiv Science

bioRxiv2021

Anti-SARS-CoV-2 human antibodies retaining neutralizing activity against SARS-CoV-2 B.1.1.529 (omicron)

SARS-CoV-2 B.1.1.529, designated omicron, was recently identified as a new variant of concern by WHO and is rapidly replacing SARS-CoV-2 delta as the most dominant variant in many countries. Unfortunately, because of the high number of mutations present in the spike of SARS-CoV-2 omicron, most monoclonal antibodies (mAbs) currently approved for treatment of COVID-19 lose their in vitro neutralizing activity against this variant. We recently described a panel of human anti-SARS-CoV-2 mAbs that potently neutralize SARS-CoV-2 Wuhan, D614G and variants alpha, beta, gamma and delta. In this work, we evaluated our mAb panel for potential in vitro activity against SARS-CoV-2 delta and omicron. Three mAbs from our panel retain neutralizing activity against both delta and omicron, with mAb 3B8 still resulting in complete neutralization at a concentration as low as 0.02 g/ml for both variants. Overall, our data indicate that mAb 3B8 may have the potential to become a game-changer in the fight against the continuously evolving SARS-CoV-2.

immunology↗

bioRxiv2021

A high-throughput neutralization assay for yellow fever serodiagnostics

Quick and accurate detection of neutralizing antibodies (nAbs) against yellow fever is essential in serodiagnosis during outbreaks, for surveillance and to evaluate vaccine efficacy in population-wide studies. All this requires serological assays that can process a large number of samples in a highly standardized format. Albeit being laborious, time-consuming and limited in throughput, classical plaque reduction neutralization test (PRNT) is still considered gold standard for the detection and quantification of nAbs due to its sensitivity and specificity. Here we report the development of an alternative fluorescence-based serological assay (SNTFLUO) with an equally high sensitivity and specificity that is fit for high-throughput testing with the potential for automation. Finally, our novel SNTFLUO was cross-validated in several reference laboratories and against international WHO standards showing its potential to be implemented in clinical use. SNTFLUO assays with similar performance are available for the Japanese encephalitis, Zika and dengue viruses amenable for differential diagnostics. IMPORTANCEFast and accurate detection of neutralizing antibodies (nAbs) against yellow fever virus (YFV) is key in yellow fever serodiagnosis, outbreak surveillance and monitoring of vaccine efficacy. Although classical PRNT still remains gold standard for measuring YFV nAbs, this methodology suffers from inherent limitations such as a low throughput and an overall high labor intensity. We present a novel fluorescence-based serum neutralization test (SNTFLUO) with equally high sensitivity and specificity that is fit for processing large number of samples in a highly standardized manner and has the potential to be implemented in clinical use. In addition, we present SNTFLUO assays with similar performance for Japanese encephalitis, Zika and dengue viruses opening new avenues for differential diagnostics.

microbiology↗