Effectiveness of COVID-19 vaccines against SARS-CoV-2 infection among persons attending the RT-PCR center at a medical college hospital in Telangana: A case- control study oleh Nagapraveen Veerapu, Dhanashree P Inamdar, Baer P Ravi Kumar, Basavaraju Anuradha, Pavitra Guddanti, Sree D Issapuri, Nikhita S Ganta, Arun Gopi