Factors Associated With the Decay of Anti-SARS-CoV-2 S1 IgG Antibodies Among Recipients of an Adenoviral Vector-Based AZD1222 and a Whole-Virion Inactivated BBV152 Vaccine oleh Sivaprakasam T. Selvavinayagam, Yean Kong Yong, Hong Yien Tan, Ying Zhang, Gurunathan Subramanian, Manivannan Rajeshkumar, Kalaivani Vasudevan, Priyanka Jayapal, Krishnasamy Narayanasamy, Dinesh Ramesh, Sampath Palani, Marie Larsson, Esaki M. Shankar, Sivadoss Raju