Neutralization of SARS-CoV-2 Variants by rVSV-ΔG-Spike-Elicited Human Sera
Yfat Yahalom-Ronen, Noam Erez, Morly Fisher, Hadas Tamir, Boaz Politi, Hagit Achdout, Sharon Melamed, Itai Glinert, Shay Weiss, Inbar Cohen-Gihon, Ofir Israeli, Marina Izak, Michal Mandelboim, Yoseph Caraco, Noa Madar-Balakirski, Adva Mechaly, Eilat Shinar, Ran Zichel, Dani Cohen, Adi Beth-Din, Anat Zvi, Hadar Marcus, Tomer Israely, Nir Paran
Abstract
The emergence of rapidly spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a major challenge to the ability of vaccines and therapeutic antibodies to provide immunity. These variants contain mutations of specific amino acids that might impede vaccine efficacy. BriLife® (rVSV-ΔG-spike) is a newly developed SARS-CoV-2 vaccine candidate currently in phase II clinical trials. It is based on a replication-competent vesicular stomatitis virus (VSV) platform. The rVSV-ΔG-spike contains several spontaneously acquired spike mutations that correspond to SARS-CoV-2 variants’ mutations. We show that human sera from BriLife® vaccinees preserve comparable neutralization titers towards alpha, gamma, and delta variants and show less than a three-fold reduction in the neutralization capacity of beta and omicron compared to the original virus. Taken together, we show that human sera from BriLife® vaccinees overall maintain a neutralizing antibody response against all tested variants. We suggest that BriLife®-acquired mutations may prove advantageous against future SARS-CoV-2 VOCs.