thrombocytopenia

That condition, called thrombosis with thrombocytopenia, happens most often in females ages 30 to 39, with about 10 cases for every million J&J doses given, Dooling said.

There were no cases of a rare but serious blood clotting side effect called thrombosis with thrombocytopenia that has been linked to the AstraZeneca vaccine developed with Oxford University researchers.

In all cases, the clots were seen in combination with low levels of blood-clotting cells, known as platelets, a condition known as thrombocytopenia.

The researchers are referring to the condition as vaccine-induced immune thrombotic thrombocytopenia.

Several of the patients also presented with thrombocytopenia, a condition where platelets in the blood that help it clot drop to unusually low levels, leading to bruising and bleeding.