Numrah Shakeel Malik, Muhammad Umair, Farah Qasim, Ayesha Azam, Muhammad Muddassar and Rimsha Qasim 2023. Does the COVID vaccine really help? A cross-sectional study to assess the positivity rate among Health Care Workers and staff members at tertiary care hospitals. Pakistan Journal of Chest Medicine. 29, 3 (Sep. 2023), 329–336. DOI:https://doi.org/10.1996/pjcm.v29i3.829.