Bhadra, S., Das, S., Biswas, S. and Pal, R. 2021. Herd Immunity: An end to the global covid 19 pandemic crises. International Research in Medical and Health Sciences. 4, 5 (Nov. 2021), 12-29. DOI:https://doi.org/10.36437/irmhs.2021.4.5.C.