Blood Groups Act as Protection Against Infection, University of Bath Study  
12/19/2012 7:46:40 AM

Humans may have acquired enzymes that make blood groups from bacteria to hinder the spread of viruses in the population, suggests a study led by scientists at the University of Bath. Red blood cells are covered with carbohydrate structures called glyco-antigens, some of them vary between individuals and are classified into blood groups A, B and O.