Subtle differences in the pathogenicity of SARS-CoV-2 variants of concern B.1.1.7 and B.1.351 in rhesus macaques

Using rhesus macaques, it was found that SARS-CoV-2 B.1.351 (South Africa variant) showed lower clinical disease severity scores and replication in the infected lungs than an early circulating D614G and B.1.1.7 (UK variant) strains. In nasal sample, cytokine and chemokine levels were remarkably elevated only in the B.1.1.7 infected animals. This study suggests that the B.1.1351 shows milder pathogenicity.