Nikhil Prasad Fact checked by:Thailand Medical News Team Sep 27, 2025 1 hour, 44 minutes ago
Medical News: Scientists discover VITT antibodies from COVID-19 vaccines can linger for years, raising questions about long-term health risks.
Researchers from McMaster University in Canada and the University of Tübingen in Germany have made an important discovery about a rare side effect linked to certain COVID-19 vaccines. The condition, called vaccine-induced immune thrombocytopenia and thrombosis (VITT), happens when the body creates antibodies that attack a blood protein known as platelet factor 4 (PF4). These antibodies can cause blood clots and dangerously low platelet levels. While VITT is rare, it can be life-threatening if not treated quickly. According to this
Medical News report, scientists have now shown that these harmful antibodies can remain in the body far longer than expected.
COVID-19 Vaccine Linked Blood Disorder Antibodies Last for Years
Tracking Patients for Almost Three Years
The study followed 30 VITT patients across Canada for nearly three years after they received adenoviral vector COVID-19 vaccines, such as AstraZeneca’s ChAdOx1 (Vaxzevria) and Johnson & Johnson’s Ad26.COV2.S. Blood samples were tested at different times to see how long the anti-PF4 antibodies stayed active. The results were striking. About 65 percent of patients still tested positive for these antibodies almost three years later, and 34 percent still carried antibodies capable of activating platelets. In comparison, similar antibodies in another condition, heparin-induced thrombocytopenia (HIT), usually disappear in less than three months.
What the Results Mean
Although the antibodies persisted, no patients in the study suffered new blood clotting events during the follow-up period. However, most of the people whose antibodies could still activate platelets stayed on long-term medication such as blood thinners or aspirin to lower their risks. Doctors noticed that even though the antibodies lingered, other blood health markers like platelet counts and clotting indicators gradually returned to normal. This suggests the body can stabilize over time, but the long-lasting presence of these antibodies raises questions about ongoing risks.
Why This Matters
The researchers warn that the full duration of these antibodies is still unknown. Some patients may carry them for years without issues, while others could be at risk if treatments are stopped too soon. The findings highlight the need for long-term monitoring of VITT patients, even if they appear healthy after recovery. The persistence of these antibodies sets VITT apart from other similar immune conditions and shows how unique the body’s reaction to adenoviral vaccines can be.
Looking Ahead
The study emphasizes that while vaccines remain crucial for protecting against COVID-19, doctors must remain aware of rare complications and continue to track patients who develop them. More research is needed to understand why these antibodies last so long and whether they pose hidden risks over time. Until then, careful follo
w-up and preventive treatments remain essential for patient safety.
The study findings were published in the peer reviewed Journal of Thrombosis and Haemostasis
https://www.sciencedirect.com/science/article/pii/S1538783625005951
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Read Also:
https://www.thailandmedical.news/news/covid-19-vaccine-causes-acquired-hemophilia-a-by-generating-autoantibodies-that-inhibit-coagulation-factors
https://www.thailandmedical.news/news/it-was-wrong-to-have-used-the-spike-proteins-in-the-covid-19-vaccines-as-they-can-elicit-many-kinds-of-pathogenic-autoantibodies
https://www.thailandmedical.news/news/new-protocol-to-treat-covid-19-vaccine-spike-disease-or-longvax-syndrome
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