Live attenuated virus vaccine protects against SARS-CoV-2 variants of concern B.1.1.7 (Alpha) and B.1.351 (Beta)
Jakob Trimpert, Julia M. Adler, Kathrin Eschke, Azza Abdelgawad, Theresa C. Firsching, Nadine Ebert, Tran Thi Nhu Thao, Achim D. Gruber, Volker Thiel, Nikolaus Osterrieder, Dušan Kunec
Abstract
Vaccines are instrumental and indispensable in the fight against the COVID-19 pandemic. Several recent SARS-CoV-2 variants are more transmissible and evade infection- or vaccine-induced protection. We constructed live attenuated vaccine candidates by large-scale recoding of the SARS-CoV-2 genome and showed that the lead candidate, designated sCPD9, protects Syrian hamsters from a challenge with ancestral virus. Here, we assessed immunogenicity and protective efficacy of sCPD9 in the Roborovski dwarf hamster, a nontransgenic rodent species that is highly susceptible to SARS-CoV-2 and severe COVID-19–like disease. We show that a single intranasal vaccination with sCPD9 elicited strong cross-neutralizing antibody responses against four current SARS-CoV-2 variants of concern, B.1.1.7 (Alpha), B.1.351 (Beta), B.1.1.28.1 (Gamma), and B.1.617.2 (Delta). The sCPD9 vaccine offered complete protection from COVID-19–like disease caused by the ancestral SARS-CoV-2 variant B.1 and the two variants of concern B.1.1.7 and B.1.351.