Garg, Vishal, Dinesh Jindal, Naveen Garg, and Rambir Singh. “HERD IMMUNITY AND COVID-19 VACCINES: AN OVERVIEW”. Tropical Journal of Pharmaceutical and Life Sciences 8, no. 1 (February 27, 2021): 10–20. Accessed September 19, 2025. http://informativejournals.com/journal/index.php/tjpls/article/view/46.