It may also explain cases in which virus carriers did not form antibodies for a year or more.

In rare cases, involving donors who were infected too recently to have formed antibodies, dangerous blood or plasma can slip through.

If you have had many blood transfusions, your body may have formed antibodies against donated blood.

If you have had many transfusions and your body has formed antibodies, you are more likely to have a reaction from donated blood.

These proteins can then be used to immunize rabbits, forming antibodies which bind to the protein.

Many pregnant women carry a fetus with a blood type different from their own, and the mother can form antibodies against fetal RBCs.

When people recover from an infection, they usually form antibodies against the microbe in the globulin portion of their blood.

Most people infected with the AIDS virus are believed to form antibodies within a few months.

Other recent studies have found that some virus carriers do not form antibodies for many months or even years.

The patients with aplasia are forming antibodies to attack the drug as if it were a foreign protein.