The ongoing SARS-CoV-2 pandemic necessitates the fast development of vaccines. Recently, viral mutants termed variants of concern (VOC) which may escape host immunity have emerged. The efficacy of spike encoding mRNA vaccines (CVnCoV and CV2CoV) against the ancestral strain and the VOC B.1.351 was tested in a K18-hACE2 transgenic mouse model. Naive mice and mice immunized with a formalin-inactivated SARS-CoV-2 preparation were used as controls. mRNA-immunized mice develop elevated SARS-CoV-2 RBD-specific antibody and neutralization titers which are readily detectable, but significantly reduced against VOC B.1.351. The mRNA vaccines fully protect from disease and mortality caused by either viral strain. SARS-CoV-2 remains undetected in swabs, lung, or brain in these groups. Despite lower neutralizing antibody titers compared to the ancestral strain BavPat1, CVnCoV and CV2CoV show complete disease protection against the novel VOC B.1.351 in our studies. Emerging SARS-CoV-2 variants with mutations in the spike protein raise concerns regarding vaccine efficacy. Here, the authors show that two spike encoding mRNA vaccines in preclinical and clinical development protect human ACE2 mice from the B.1.351 variant of concern and ancestral B BavPat1.
【저자키워드】 SARS-CoV-2, Vaccines, 【초록키워드】 Efficacy, Vaccine, Mutation, Mortality, antibody, mRNA vaccine, VoC, B.1.351, SARS-CoV-2 pandemic, SARS-CoV-2 variant, vaccine efficacy, variants of concern, lung, variants, Brain, Spike protein, hACE2, mRNA vaccines, human ACE2, Viral, SARS-CoV-2 variants, mice, mRNA, swabs, mutant, disease, Antibody titers, Neutralizing antibody titer, neutralization titers, K18-hACE2, viral strain, formalin, CVnCoV, B.1.351 variant, host immunity, clinical development, neutralization titer, Complete, controls, Transgenic mouse, immunized, raise, BavPat1, PROTECT, develop, caused, significantly, detectable, elevated, reduced, were used, the spike protein, groups, was tested, 【제목키워드】 human ACE2, transgenic mice, BavPat1, PROTECT,