Partial vaccination did not substantially alleviate the severity of delta variant infection, while full vaccination significantly ameliorated the condition of the patients by amending coagulation dysfunction (including thrombocytopenia, prolonged aPPT, and thrombin time) and extenuating viremic impact on major organs (typified by reduced levels of ALP, ADA, BUN, creatinine, and LDH). Here, ADA is linked to Thrombocytopenia.