Numrah Shakeel Malik; Muhammad Umair; Farah Qasim; Ayesha Azam; Muhammad Muddassar; Rimsha Qasim. 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. Pak J Chest Med 2023, 29, 329-336.