To study the effect of 'Covishield' vaccination on pre-donation platelet counts of plateletpheresis donors.

INTRODUCTION: Approximately 55.52% of the Indian population had been fully vaccinated by Jan. 2022, since its first roll out on January 16, 2021. A few concerns were raised concerning the Covishield vaccination related to thrombotic thrombocytopenia. Apheresis-derived platelet concentrates are frequently required in a plethora of clinical situations and post-vaccination decrement of platelet counts might lead to increased deferral of the platelet-pheresis donors. OBJECTIVES: The aim of the study was to discover the effect of the Covishield vaccination on deferral rates of plateletpheresis donors. METHODS: Blood samples were collected from the potential platelet donors for the completion of the standard questionnaire for the complete blood count. The data collected were tabulated in the MS Excel spreadsheet and the biostatistical analysis was performed with the SPSS v23. A p-value of < 0.05 was taken as significant. We compared this data with age- and sex-matched controls. RESULTS: The mean age of cases and controls was 29.69 ± 8.57 and 30.15 ± 7.11, respectively. There was a significant difference in platelet counts of cases (188496.35 ± 72065.66/cumm) and controls (269524.50 ± 53981.60/cumm). Furthermore, donors who received one dose had higher platelet counts of 248676.47 ± 80075.24/cumm than those who received both doses of vaccine (179970.83 ± 66773.73/cumm) . The difference in deferral rates between the two groups was remarkable (34.7% vs. 0.9%, with the p-value < 0.001). CONCLUSION: Vaccination certainly increased the deferral rates of plateletpheresis donors due to low platelet counts. Average platelet counts were low in fully vaccinated individuals, however, the platelets returned to normal counts as the post-vaccination days progressed.

COVID-19 vaccine humoral response in frequent platelet donors with plateletpheresis-associated lymphopenia.

BACKGROUND: Plateletpheresis involves platelet separation and collection from whole blood while other blood cells are returned to the donor. Because platelets are replaced faster than red blood cells, as many as 24 donations can be done annually. However, some frequent apheresis platelet donors (>20 donations annually) display severe plateletpheresis-associated lymphopenia; in particular, CD4+ T but not B cell numbers are decreased. COVID-19 vaccination thereby provides a model to assess whether lymphopenic platelet donors present compromised humoral immune responses. STUDY DESIGN AND METHODS: We assessed vaccine responses following 2 doses of COVID-19 vaccination in a cohort of 43 plateletpheresis donors with a range of pre-vaccination CD4+ T cell counts (76-1537 cells/µl). In addition to baseline T cell measurements, antibody binding assays to full-length Spike and the Receptor Binding Domain (RBD) were performed pre- and post-vaccination. Furthermore, pseudo-particle neutralization and antibody-dependent cellular cytotoxicity assays were conducted to measure antibody functionality. RESULTS: Participants were stratified into two groups: <400 CD4/µl (n = 27) and ≥ 400 CD4/µl (n = 16). Following the first dose, 79% seroconverted within the <400 CD4/µl group compared to 87% in the ≥400 CD4/µl group; all donors were seropositive post-second dose with significant increases in antibody levels. Importantly differences in CD4+ T cell levels minimally impacted neutralization, Spike recognition, and IgG Fc-mediated effector functions. DISCUSSION: Overall, our results indicate that lymphopenic plateletpheresis donors do not exhibit significant immune dysfunction; they have retained the T and B cell functionality necessary for potent antibody responses after vaccination.

Challenges in platelet inventory management at a tertiary care oncology center during the novel coronavirus disease (COVID-19) pandemic lockdown in India.

The novel coronavirus disease (COVID-19) has been declared a pandemic by the world health organization and to limit the spread of the disease, many countries in the world, including India, had enforced a lockdown. Despite no restriction over the platelet donation activities, plateletpheresis donors became apprehensive regarding the possible risk of spread of the COVID-19 during the platelet donation and in the hospital premises. Many of them started hesitating for platelet donations. With this, the blood center started having an acute shortage of platelets. Various confidence-building steps were implemented by the blood center to promote voluntary plateletpheresis. The blood center staff and individual donors were educated to prevent the spread of COVID-19. The donor organizations and plateletpheresis donors were informed about the steps to be taken by the blood center during the donation and necessary steps for the prevention of the possible spread of COVID-19. With the help of these measures, the confidence of the individual platelet donors and the donor organizations was restored in the blood center and regular plateletpheresis was continued. These measures may also be useful to other blood centers in the COVID-19 pandemic and this experience may be useful if a similar pandemic lockdown happens in the future.