Viral enhancement hypothesis. In this figure, we propose that EBV and HHV-6 lytic replication induces change in ACE expression so as to increase the binding between the SARS-CoV-2 S-protein and the ACE2 receptor, thus enhancing SARS-CoV-2 binding to epithelial cells. (A) Just SARS-CoV-2, three spike proteins bind to ACE-2. Infection with SARS-CoV-2 causes a cell expression of ACE-2 receptor that matches with 3 spikes on the SARS-CoV-2 virus. (B) SARS-CoV-2 + EBV, four spike proteins bind to AC E-2. Infection with SARS-CoV-2 and EBV causes an expression of the ACE-2 receptor that matches 4 spikes on the virus. (C) SARS-CoV-2 + EBV + HHV-6, five spike proteins bind to ACE-2. Infection with SARS-CoV-2, EBV and HHV-6 causes expression of ACE-2 receptor that binds to the virus with 5 spikes for a perfect match.