Ostadgavahi, Ali Toloue, Ryan Booth, Gary Sisson, Nichole McMullen, Michelle Warhuus, Peter Robertson, Matthew Miller, Wanda C Allen, May El Sherif, Robert Brownlie, Darryl Falzarano, and Christopher D Richardson. “Heterologous Immunization With Covishield and Pfizer Vaccines Against SARS-CoV-2 Elicits a Robust Humoral Immune Response”. The Journal of Infection in Developing Countries 15, no. 05 (May 31, 2021): 653-656. Accessed June 24, 2021. https://jidc.org/index.php/journal/article/view/34106888.