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Covid-19 Vaccines, Immunity, And Effect On Children

So, what are ‘spike’ proteins? In brief, the viral envelope of coronaviruses is made up of 3 proteins, the membrane protein (M), the envelope protein (E), and the spike protein (S). The S protein is a highly glycosylated and large type-I transmembrane fusion protein that plays a crucial role in penetrating host cells and initiating infection (Figure 1). Spike proteins of coronaviruses can be divided into two important functional subunits, S1 subunit, which forms the globular head of the S protein, and S2 that forms the stalk of the protein and is directly embedded into the viral envelope. Upon interaction with a potential host cell, the S1 subunit will recognize and bind to receptors on the host cell, whereas the S2 subunit, which is the most conserved component of the S protein, will be responsible for fusing the envelope of the virus with the host cell membrane [1].