5Prevalence of Blood Types by Population
It is not easy to determine the rarest type of blood in the world as it is associated with certain genetic factors. Overall, the prevalence of blood types can vary across geographic regions and populations. O blood types are the most common as they account for up to 63 percent of the world’s population. This number is even higher in South and Central America. In Central Asia and Eastern Europe, B blood types are more common, while O blood types are less prevalent. But across the world, B blood groups are the least common with only 16 percent of the world’s population. Concerning the Rh factor, Rh-blood is less common than Rh+. [5]
