SARS-CoV-2 Spike-Envelope-Membrane (SEM) mosaic protein (SEM mosaic protein)

The SARS-CoV-2 SEM mosaic protein is an engineered vaccine antigen that incorporates the three primary structural proteins of the virus: Spike (S), Envelope (E), and Membrane (M) [1]. While most first-generation COVID-19 vaccines focus exclusively on the Spike protein, the SEM mosaic approach aims to broaden the immune response by including more conserved regions found in the E and M proteins [2]. This strategy is intended to provide more robust protection against emerging variants and potentially other betacoronaviruses by eliciting both neutralizing antibodies and a broad T-cell response [1, 2]. In a therapeutic context, this protein is typically delivered via enveloped virus-like particles (eVLPs) that mimic the native structure of the virus to enhance immunogenicity [3]. By targeting multiple structural components, these vaccines may reduce the risk of immune escape compared to Spike-only formulations [2]. This target is currently being evaluated in clinical trials for pan-coronavirus vaccine candidates like VBI-2901 [1, 3]. Sources: [1] VBI Vaccines Inc. (2021). "VBI-2900: Pan-Coronavirus Vaccine Program." [2] Nature Reviews Immunology (2021). "Broadly neutralizing antibodies and T cell responses to SARS-CoV-2." [3] ClinicalTrials.gov. "Phase 1/2 Study of VBI-2902." NCT04773665.

Other names

S-E-M mosaic antigenSARS-CoV-2 multi-antigenic structural proteinVBI-2901 antigenSpike-Envelope-Membrane eVLPPan-coronavirus mosaic antigen

Active immunization through the presentation of multiple conserved viral epitopes to the immune system, inducing neutralizing antibodies and T-cell activation.