SARS-CoV-2 Challenge in Transgenic Mice

8–10-week-old BALB/c female mice (Charles River) were immunised with DNA or MVA constructs bearing the gene of interest, and serial bleeds were taken from the saphenous vein. Terminal bleeds were taken via cardiac puncture under isofluorane anaesthesia. For challenge studies, animals were transduced with 1x10⁷ PFU of the ad5-huACE-2 vector in a volume of 75ul by intranasal route (University of Iowa, Viral Vector Core) five days before infection with SARS-CoV-2. Mice were then moved to hermetically sealed isocages at containment level 3 and administered 1x10⁴ PFU of Australia/VIC01/2020 (SARS-CoV-2) by intranasal route under light isofluorane anaesthesia, in a total volume of 40 µl PBS. Animals were weighed and checked twice daily for clinical symptoms and culled on days 3 and 6 post infection by terminal bleed under non recovery anaesthesia. All animal work was approved by the Home Office under project licence P8143424B and approved by the Animal Welfare Ethical Review Body (AWERB). Animal experiments were performed in early 2020 when K18-huACE2 mice colonies were being expanded and were not available.