The concept of herd immunity, or community immunity, has sparked debate about whether it would control the spread of COIVD-19. According to the Centers for Disease Control and Prevention (CDC), herd immunity is a situation in which sufficient proportions of a population are immune to an infectious disease to make its spread from person to person unlikely. "Herd immunity basically means, if you could envision a circle, let's say, of 100 people inside this circle and if you can imagine the suscept