Study Exclusion reasons Remarks Reference(s)
Candidate COVID-19 Vaccine (COV001), 2020 randomized controlled trial

Folegatti PM Lancet 2020 Aug 15;396(10249):467-478. 10.1016/S0140-6736(20)31604-4

NCT04276896, 0 single-arm no control group  
Barrett, 2020 - no control group phase 1/2

Barrett JR et al. Nat Med 10.1038/s41591-020-01179-4

Babamahmoodi, 2021 observational study no control group

Babamahmoodi F et al. researchsquare 10.21203/

Tobaiqy M, 2021 case series no control group retrospective descriptive study using spontaneous reports submitted to the EV database in the period from 17 February to 12 March 2021

Tobaiqy M Vaccines (Basel) 2021 Apr 16;9(4):393. 10.3390/vaccines9040393

Nanthapisal, 2022 randomized controlled trial no clinically relevant endpoint To evaluate immunogenicity and reactogenicity of standard- versus low-doseChAdOx1 nCoV-19 vaccine booster after CoronaVac in healthy adults

Nanthapisal S et al. medrxiv;2022.02.15.22270974v1 10.1101/2022.02.15.22270974