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...
AB can only donate blood to other ABs. A can donate blood to As and ABs. B can donate blood to Bs and ABs. O can donate to all blood types. Negative Rh factors can donate toâ¦ both positive and negative Rh factors, however postive Rh factors can only donate to other positive. So if I had O+ blood, I couldn't donate to A-, but could donate to A+.