People with type A blood are likely more susceptible to COVID-19 infections, because the spike protein of the virus shows an affinity for blood group A cells, according to a new study in Blood. This is the strongest evidence to date to support the idea that blood types influence who is more likely to contract COVID-19. Moreover, the study shows the spike protein's affinity for type A cells may be amplified by the Omicron strain of the virus. 25% to 50% increased infection for type A The study looked at the receptor binding domain (RBD) of SARS-CoV-2, which facilitates host...