section_path: Pathophysiology/Viral and host factors/Virus proteins
section_name: Virus proteins
paragraph_text: Virus proteins
  
  Multiple viral and host factors affect the pathogenesis of the virus. The S-protein, otherwise known as the spike protein, is the viral component that attaches to the host receptor via the ACE2 receptors. It includes two subunits: S1 and S2.
  
  Studies have shown that S1 domain induced IgG and IgA antibody levels at a much higher capacity. It is the focus spike proteins expression that are involved in many effective COVID‑19 vaccines.
  
  The M protein is the viral protein responsible for the transmembrane transport of nutrients. It is the cause of the bud release and the formation of the viral envelope. The N and E protein are accessory proteins that interfere with the host's immune response.