Extensive neutralization against SARS-CoV-2 variants elicited by Omicron-specific subunit vaccine as a heterologous booster

Running title:  Neutralization elicited by Omicron-specific subunit vaccine booster

Pai Peng*, Chengqian Feng*, Jie Hu*, Chang-long He*, Hai-jun Deng*,  Qinghong Fan，Jin Xiang, Guofang Tang，Mengling Jiang，Fengyu Hu, Feng Li, Kai Wang, Ni Tang, Xiaoping Tang#, Ai-long Huang#

* These authors contributed equally to this work.

Summary

To overcome the increased risk of SARS-CoV-2 reinfection or post-vaccination infection caused by the Omicron variant, Omicron-specific vaccines were considered a potential strategy. We reported the increased magnitude and breadth of antibody response against VOCs elicited by post-vaccination Delta and Omicron infection, compared to WT infection without vaccination. Then, in mouse models, three doses of Omicron-RBD immunization elicited comparable neutralizing antibody (NAb) titers with three doses of WT-RBD immunization, but the neutralizing activity was not cross-active. By contrast, a heterologous Omicron-RBD booster following two doses of WT-RBD immunization increased the NAb titers against Omicron by 9 folds than the homologous WT-RBD booster. Moreover, it retains neutralization against both WT and current VOCs. Results suggest that Omicron-specific subunit booster shows its advantages in the immune protection from both WT and current VOCs and that SARS-CoV-2 vaccines including two or more virus lineages might improve the NAb response.

Keywords

SARS-CoV-2Omicronpost-vaccination infectionRBD subunit proteinvaccine

Schematic of BALB/c mice immunization programs. 6 mice for each group were intramuscularly injected with the indicated recombinant proteins or the adjuvant as control.

Highlights:

●Post-vaccination SARS-CoV-2 infection can elicit higher and boarder immune response

●A heterologous booster with the Omicron-RBD protein elicits a 9-fold increased NAb

●Heterologous boosting with Omicron enhance the potency and breadth of immune response

Doi: https://doi.org/10.1101/2022.03.07.483373 

Preprint full text: https://www.biorxiv.org/content/10.1101/2022.03.07.483373v1 

Published version:  https://www.sciencedirect.com/science/article/pii/S2589004222017370

https://doi.org/10.1016/j.isci.2022.105465