The Warsaw Treaty Organization (also known as the Warsaw Pact) was a political and military alliance established on May 14, 1955 between the Soviet Union and several Eastern European countries.
1 Donors with blood type A... can donate to recipients with blood types A and AB. 2  Donors with blood type B... can donate to recipients with blood types B and AB.  Donors with blood type AB...
In theory, type O blood is the universal donor. It can donate to A, B, or AB. In reality, things are more complicated, and you can't really say what type of blood O can donate â¦ to, not without doing some lab tests on the specific blood (donor and recipient both).