Real-world effectiveness of the inactivated COVID-19 vaccines against variant of concerns: meta-analysis oleh Muhammad Usman Sarwar, Fathimathuz Zehra Waasia, Akram Ahmed Aloqbi, Maher Alandiyjany, Reem Mohammed Alqahtani, Lubna Abdulrahman Hafiz, Ghalia Shamlan, Mohammed Albreiki