SARS2 and infection: In-line with reports showing adult C57BL/6J mice are resistant to SARS-CoV-2 infection, neither SARS-CoV-2 nor rVSV-SARS2-S were able to infect neonatal C57BL/6J mice even when deficient in type I interferons indicating that the absolute requirement for spike-hACE2 interaction for establishing infection extends to neonatal mice (14, 44).