PERSISTENT COAGULATION ABNORMALITIES IN RECOVERED COVID-19 PATIENTS FOLLOWING VACCINATION: A RETROSPECTIVE ANALYSIS

This retrospective observational study assessed persistent coagulation abnormalities in individuals who recovered from COVID-19 and subsequently received two doses of COVID-19 vaccination. The study enrolled 250 individuals, aged 20–50 years, and evaluated four primary coagulation markers: prothrombin time, activated partial thromboplastin time, D-dimer, and fibrinogen. Blood samples were analyzed using the STA-R coagulation analyzer. Results indicated that 10% of participants exhibited elevated D-dimer levels, 34% had elevated prothrombin times, and 85% displayed prolonged activated partial thromboplastin times, while 7.2% showed increased fibrinogen levels. Statistical analysis revealed significant deviations in D-dimer, activated partial thromboplastin time, and fibrinogen from standard reference ranges. These abnormalities suggest a possible hypercoagulable state post-vaccination, potentially due to vaccine-induced mechanisms that activate coagulation pathways. Findings align with reports of vaccine-induced thrombotic complications, especially in adenovirus-vectored vaccines. This study underscores the importance of monitoring coagulation parameters in vaccinated individuals with prior COVID-19 infection to ensure vaccine safety and efficacy. Future studies should investigate the underlying mechanisms of these coagulation changes and their clinical implications.