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

Peng, P.; Feng, C.; Hu, J.; He, C.-l.; Deng, H.; Fan, Q.; Tang, G.; Jiang, M.; Hu, F.; Li, F.; Wang, K.; Tang, N.; Tang, X.; Huang, A.

doi:10.1101/2022.03.07.483373

bioRxiv · 10.1101/2022.03.07.483373

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

Peng, P.·Feng, C.·Hu, J.·He, C.-l.·Deng, H.·Fan, Q.·Tang, G.·Jiang, M.·Hu, F.·Li, F.·Wang, K.·Tang, N.·Tang, X.·Huang, A.

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Abstract

The currently dominant variant of SARS-CoV-2 Omicron, carrying a great number of mutations, has been verified its strong capacity of immune escape in COVID-19 convalescents and vaccinated individuals. An increased risk of SARS-CoV-2 reinfection or breakthrough infection should be concerned. Here we reported higher humoral immune response elicited by Delta and Omicron variants after breaking through previous infection and cross-neutralization against VOCs, compared to the ancestral wild-type (WT) virus infection. To overcome the immune escape of Omicron, Omicron-specific vaccine was considered as a novel and potential strategy. Mouse models were used to verify whether Omicron-specific RBD subunit boost immune response by immunizing Omicron-RBD recombinant proteins. Three doses of Omicron-RBD immunization elicit comparable neutralizing antibody (NAb) titers with three doses of WT-RBD immunization, but the neutralizing activity was not cross-active. By contrast, two doses of WT-RBD with an Omicron-RBD booster increased the NAb geometric mean titers against Omicron by 9 folds. Moreover, an additional boost vaccination with Omicron-RBD protein could increase humoral immune response against both WT and current VOCs. These results suggest that the Omicron-specific subunit booster shows its advantages in the immune protection from both WT and current VOCs, and that SARS-CoV-2 vaccines administration using two or more virus lineages as antigens might improve the NAb response.

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Peng, P., Feng, C., Hu, J., He, C.-l., Deng, H., Fan, Q., Tang, G., Jiang, M., Hu, F., Li, F., Wang, K., Tang, N., Tang, X., Huang, A.. 2022-03-08. Extensive neutralization against SARS-CoV-2 variants elicited by Omicron-specific subunit vaccine booster. https://doi.org/10.1101/2022.03.07.483373

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