Vaccine Induced Immune Thrombotic Thrombocytopenia After Sinopharm Vaccination: A Systematic Review of Case Reports

Vaccine-induced thrombotic thrombocytopenia (VITT) has been linked to vector-based vaccines, but only four cases following whole-virus vaccines (Sinopharm) have been reported, as far as we are aware. This systematic review aimed to compile the clinical and laboratory results of VITT development after Sinopharm vaccination. We searched PubMed, ScienceDirect, and Google Scholar using pertinent keywords. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed when conducting the search. Inclusion criteria were human case studies, published in English, and freely available in full text. Of the 256 studies initially identified, 4 (1.56%) were analyzed. Mean age was 55.5 years (range: 18-85). There were 3 males and 1 female as per gender distribution. The most common symptom reported was sudden and extreme pain in the lower extremity (n = 2). The mean duration from the time of vaccination to admission was 7 days, and the average platelet count was 54.38 X 10⁹ /L. All (n = 4) cases had thrombocytopenia. VITT was definitively diagnosed according to ASH Criteria for VITT in 2 case reports. VITT adapted 4Ts scoring system showed high probability (8) in all (n = 4) cases. Intravenous immunoglobin (IVIG) was administered in 3 VITT patients, and all patients (n = 4) have successfully recovered. Early recognition and timely treatment improve patient prognosis.