1. World Health Organization. Coronavirus disease (COVID-19) outbreak.https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200624-covid-19-sitrep-156.pdf?sfvrsn=af42e480_2.
2. World Health Organization. Coronavirus disease 2019 (COVID-19) Situation Report -181. https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200719-covid-19-sitrep-181.pdf?sfvrsn=82352496_2.
3. Activation of the SARS coronavirus spike protein via sequential proteolytic cleavage at two distinct sites;Belouzard;Proc Natl Acad Sci U S A,2009
4. The coronavirus spike protein is a class I virus fusion protein: structural and functional characterization of the fusion core complex;Bosch;J Virol,2003
5. Coronavirus cell entry occurs through the endo-/lysosomal pathway in a proteolysis-dependent manner;Burkard;PLoS Pathog,2014