SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), also known as novel coronavirus 2019-nCoV, causes fever, severe respiratory illness, and can lead to life threatening pneumonia. The first cases of this disease, termed COVID-19 for coronavirus disease 2019, have been detected in December 2019 in Wuhan, China. Since that time, the virus kept mutating, leading to new virus variants. The B.1.1.529 lineage, also known as Omicron variant, is a SARS-CoV-2 variant that was first discovered in South Africa and Botswana in November 2021. The variant has been further classified into sublineages, such as BA.1, BA.2, BA.4, and BA.5.
In total there are 34 mutations in the surface or spike glycoprotein of the B.1.1.529/BA.5 lineage compared to the Wuhan variant (reference genome GenBank MN908947.3): T19I, L24 deletion, P25 deletion, P26 deletion, A27S, H69 deletion, V70 deletion, G142D, V213G, G339D, S371F, S373P, S375F, T376A, D405N, R408S, K417N, N440K, L452R, S477N, T478K, E484A, F486V, Q498R, N501Y, Y505H, D614G, H655Y, N679K, P681H, N764K, D796Y, Q954H, N969K.
SARS-CoV-2 Prot_S stands for the surface glycoprotein of SARS-CoV-2, the “spike protein”. This protein is responsible for recognition and binding of the coronavirus to the host cell. Once SARS-CoV-2 has bound to the ACE2 receptor of the host cell, fusion of viral envelope and host cell membrane starts, which enables the viral genome to enter the host cell. Thus, the spike protein is crucial for the infection of cells with coronaviruses and has been used as a target for vaccine development. The PepTivator SARS-CoV-2 Prot_S Complete BA.5 covers the whole protein coding sequence of the spike protein of the SARS-CoV-2 B.1.1.529/BA.5 lineage without the first four amino acids of the signal peptide.