Vaccines against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have been highly efficient in protecting against Coronavirus Disease 2019 (COVID-19). However, the emergence of viral variants that are more transmissible and, in some cases, escape from neutralizing antibody responses has raised concerns. Here, we evaluated recombinant protein spike antigens derived from wild-type SARS-CoV-2 and from variants B.1.1.7, B.1.351, and P.1 for their immunogenicity and protective effect in vivo against challenge with wild-type SARS-CoV-2 in the mouse model. All proteins induced high neutralizing antibodies against the respective viruses but also induced high cross-neutralizing antibody responses. The decline in neutralizing titers between variants was moderate, with B.1.1.7-vaccinated animals having a maximum fold reduction of 4.8 against B.1.351 virus. P.1 induced the most cross-reactive antibody responses but was also the least immunogenic in terms of homologous neutralization titers. However, all antigens protected from challenge with wild-type SARS-CoV-2 in a mouse model. This study explores the immune response induced by wild type and variant SARS-CoV-2 spike proteins, and the protection that these immune responses provide against challenge with wild type virus in the mouse model.
【초록키워드】 COVID-19, coronavirus disease, severe acute respiratory syndrome coronavirus 2, viruses, neutralizing antibody, SARS-CoV-2, Coronavirus disease 2019, coronavirus, immune response, Neutralizing antibodies, antibody, B.1.351, variant, severe acute respiratory syndrome Coronavirus, virus, coronavirus 2, variants, Antigen, Protein, Viral, B.1.1.7, P.1, immune responses, response, Viral variants, respiratory, in vivo, mouse model, homologous, viral variant, moderate, wild type, Neutralizing antibody response, protective effect, neutralization titers, Neutralizing titer, Spike proteins, cross-reactive antibody, in some, reduction, acute respiratory syndrome coronavirus, SARS-CoV-2 spike proteins, neutralizing antibody responses, wild-type SARS-CoV-2, immunogenic, neutralizing titers, responses, evaluated, raised, cross-neutralizing, 【제목키워드】 SARS-CoV-2 variant, mice, wild-type virus, PROTECT,