4992 | Candidate COVID-19 Vaccine (COV001), 2020 | 2 | 1 | 0 | excluded | risk of bias not avaialble | |
6444 | Barrett, 2020 | 2 | 0 | 0 | excluded | risk of bias not avaialble | |
9070 | Tobaiqy M, 2021 | 2 | 32 | 0 | excluded | not a RCT | risk of bias not avaialble |
9376 | Nanthapisal, 2022 | 2 | 1 | 0 | excluded | risk of bias not avaialble |