Table 2.

Possible prophylactic regimens against SARS-CoV-2 infection

Agent	Mechanism of Action	Regimen	Reference
VitA	Antioxidant, anti-inflammatory, immune-regulatory agent	6 000 IU/d for 2 weeks	97-99
VitC		1)intravenous 200 mg/kg body weight/d, divided into 4 doses for ICU-care patients 2)oral 6 g/d 3)one 10–20 g IV (max: 1.5 g/kg)	98-100
VitD		10 000 IU/d for 2 weeks until the 25(OH)Vit D level reaches 40–60 ng/mL and then 5 000 IU/d	101
Zinc	Antioxidant, anti-inflammatory, immune-regulatory agent, intracellular signal molecule in immune cells, RdRP inhibitor	Max: 1 mg/d	102-106
Hydroxychloroquine sulfate	Antigen-presenting cell lysosomal pH modulator; toll-like receptor family inhibitor; hemozoin biocrystalization inhibitor; altering the ACE2 glycosylation, which inhibits S-protein binding and phagocytosis	200 mg/d	74

IU, International unit; mg, Milligrams; kg, Kilograms; ICU, Intensive care unit; g, Grams; IV, Intravenous; Vit, Vitamin; ng, Nanograms; mL, Milliliter