A man in his 70s from Washington DC experienced severe bleeding, which has been linked to a rare side effect of his Covid booster shot. He sought medical attention after noticing blood in his stool, initially attributing it to a recent colonoscopy.
During his examination, doctors observed significant bruising on both arms, which had developed rapidly. Tests indicated he had hemophilia A, a condition where the body struggles to form blood clots, leading to prolonged bleeding.
This extended bleeding can cause bruises due to blood pooling under the skin, making individuals more prone to injuries. In his case, since he had recently undergone a colorectal procedure, most of the bleeding was internal, visible only in his stool.
Interestingly, the man had no family history of this condition and wasn’t actively bleeding when examined. However, his symptoms were traced back to about a week after he received his fifth dose of the Moderna Covid vaccine booster.
Doctors theorized that the vaccine might have caused his immune system to produce antibodies that interfered with his body’s clotting mechanism, leading to this disorder.
Typically, mRNA vaccines work by prompting the immune system to attack the Covid virus. Yet, in this case, it seems possible that the vaccine also confused the body’s recognition of its own cells, generating antibodies against the clotting process.
Experts noted that adverse reactions to Covid vaccines are rare and that the benefits generally outweigh the risks of complications.
In reviewing similar cases from 2020 to 2022, it was found that many patients developed acquired hemophilia A (AHA) after receiving Covid vaccinations, usually in their 70s, with symptoms often appearing roughly 14 days post-vaccination. AHA can be serious, with around 10.3% of cases being fatal, underscoring the importance of early diagnosis and treatment.
AHA can lead to various bleeding issues, including internal bleeding. The exact mechanism by which the vaccine triggered the production of clotting antibodies remains unclear.
Most AHA cases arose after initial or second doses of the vaccine; however, this particular man’s situation is notable as it occurred after his fifth dose. Initial tests showed normal white cell and platelet counts, but over time, the bruising escalated, prompting further blood tests that revealed harmful antibodies affecting his clotting ability.
Further analysis found his FVIII levels—crucial for blood clot formation—were alarmingly low, leading to his diagnosis of acquired hemophilia A, a condition known to target this specific protein.
Typical symptoms include nosebleeds, widespread bruising, and gastrointestinal bleeding. Patients can face complications from uncontrolled bleeding during trauma or surgery, and while AHA is often treatable, life-threatening complications can occur.
Experts estimate approximately two cases of AHA arise per million people in the US, translating to nearly 1,000 cases annually in a population of about 340 million.
The elderly man has since been advised to visit a hematology clinic weekly and has started treatment with cyclophosphamide, an immunosuppressant. As his FVIII levels improved and he showed positive signs of recovery, his medication dosage was gradually reduced, along with additional medications to prevent fungal infections and protect his stomach.
