Some Safety Concerns about Vaccines A report raised alarm about at least 36 people who developed a rare, lethal blood disorder, called thrombocytopenia, after receiving either of the two approved COVID-19 vaccines in the US. A Miami obstetrician, Gregory Michael, just 56, died of a brain hemorrhage just 16 days after receiving a Pfizer vaccination. His thrombocytopenia had caused his platelets to drop to virtually zero. A Johns Hopkins University expert on blood disorders, Jerry L. Spivak, who was uninvolved in Michael’s care, said that based on Michael’s wife’s description: “I think it is a medical certainty that the vaccine was related [to Michael’s death].”