Mohamed Bulla, H. A. “COVID -19: EFFICACY AND SAFETY PROFILE OF MAIN VACCINES APPROVED FOR EMERGENCY USE AUTHORIZATION IN 2021”. International Journal of Research -GRANTHAALAYAH, vol. 9, no. 7, Aug. 2021, pp. 271-83, doi:10.29121/granthaalayah.v9.i7.2021.4062.