2.3. Shake flask virus studies

For virus infection studies in shake flasks, suspension‐adapted Vero cells from the late exponential growth phase were harvested, if required pooled, and seeded at the indicated cell density in a fresh medium. Vero cells were infected with rVSV at the indicated MOI and the temperature was shifted to either 34°C (rVSV‐ZEBOV, rVSV‐HIV) or 31°C (rVSV_Ind‐msp‐S_F‐Gtc). Samples for virus titration were centrifuged for 5 min at 1200×g to remove cellular debris, aliquoted, and stored at −80°C.