To Study the Effect of Covishield Vaccinationon Platelet Counts of Plateletpheresis Donors-A Pilot Study

ABSTRACT

Introduction: About 20% of the Indian population has been vaccinated till September, since its first roll out on 16 January 2021.Majority of Indian population was vaccinated through ChAdOx1nCoV-19 Corona Virus Vaccine (Recombinant), commonly known asCovishield. Although the vaccine is proven safe but occasional reports of Vaccine-induced thrombocytopenia and thrombosis raisedfew eyebrows regarding the safety. Apheresis-derived platelet concentrates are frequently required in all sorts of clinical illnesses andpost-vaccination decrement of platelet counts might lead to increaseddeferral of the plateletpheresis donors.Aims &Objectives: The study aims to find out the effect of Covishield vaccination on deferral rates of plateletpheresis donors. Theprimary objective is to compare deferral rates of vaccinated plateletdonors (cases) from non-vaccinated ones (control) and the secondaryobjective is to correlate vaccination with pre-donation platelet countsof the donors.Materials &Methods: A blood sample was collected from thepotential platelet donors after the standard questionnaire for a complete blood count. Data collected were tabulated in an MS Excelspreadsheet and was analyzed with SPSS v23, p-value ≥ 0.05 wastaken as significant. We compared this data with an equal number ofage and sex-matched platelet donors (controls) from the year 2019.Result: The mean age of cases and controls was 29.69 ± 8.57 and30.15 ± 7.11 respectively. There is a marked difference betweenplatelet counts of cases (188,496.35 ± 72,065.66/mm3) and controls(269,524.50 ± 53,981.60/mm3) with p-value of <0 > 3 than thosewho received 2 doses 179,970.83 ± 66,773.73/mm3. The differencein deferral rates was remarkable between the two groups 34.7% vs0.9% with p-value <0.001. Weak positive correlation is establishedbetween days after 2nd dose and platelet count (rho = 0.2, p = 0.002).Conclusions: Vaccination undoubtedly increased the deferral rates ofplateletpheresis donors due to low platelet counts. Average plateletcounts were low in fully vaccinated individuals, however, plateletreturned to normal counts as the days progress post-vaccination.