The effects of quercetin and heat shock on viral titre. Vero cells were heated (HS) or not (Ctrl) or treated with quercetin (100 μM; QCT) or not (DMSO). Twelve hours later, cells were inoculated with PEDV at an MOI of 1. The viral titers of cell supernatants were determined at 12 hpi and 24 hpi. Data are mean ± SD (n = 3, *p < 0.05). A Viral titre after 12 h. B Viral titre after 24 h.