The work performed in NUS/NUHS was supported by NUHS Research Office under Project Number NUHSRO/2020/033/RO5+5/CORONAVIRUS/LOA (WBS R-571-000-071-733). The work performed in IMCB and BII was also supported by A*STAR through intramural funding and an A*CRUSE gap funding (ACCL/19-GAP064-R20H-F).