PROS1 and COVID-19: Mice and hamsters inoculated with trimeric S protein vaccine were not infected with SARS-CoV, but the serum produced could promote the entry of ACE2-independent pseudovirus.221 Rhesus monkeys inoculated with a high dose of COVID-19 vaccine had elevated body temperature within 1 day, increased respiratory rate, and decreased appetite within 9–16 days.216 Monkeys euthanized on days 3 and 21 displayed multifocal lung injury, alveolar septum thickening due to edema and fibrin, the slight appearance of type II lung cells, and perivascular lymphocyte proliferation.214