<![CDATA[Background: mRNA vaccines have been associated with idiopathic thrombocytopenic purpura (ITP). The development of inactivated vaccines and the addition of adjuvants, such as aluminum salts (alum) and cytosine-phosphate-guanine (CpG), are expected to enhance their safety and effectiveness. Objective: We examined the changes in hematological profiles in response to various doses of a recombinant SARS-CoV-2 protein subunit vaccine formulated with Alum and CpG oligodeoxynucleotide 1018 (CpG 1018). Methods: This research involved an analysis of data from a Phase I, observer-blind, randomized, controlled trial in healthy participants aged–18-70 years old in Indonesia. The subjects were divided into five groups: Sinovac® (A), 12.5 µg of SARS-CoV-2 RBD subunit recombinant protein and 750 µg (group B) or 1500 µg (group C) Alum+CpG1018, 25 µg of SARS-CoV-2 RBD subunit recombinant protein and 750 µg (group D) or 1500 µg (group E) Alum+CpG1018. Hematological parameter fluctuations were compared from baseline (V0), 7 days after the initial dose (V1a), and 14 days after the second dose (V2a). Results: There were no significant differences in red blood cell parameters between the groups after vaccination. Platelet levels were stable in all groups at all time points. The different leukocyte counts showed a slight fluctuation in neutrophils, eosinophils, lymphocytes, and monocytes during the study. All hematological changes were within the normal range. Conclusion: Variation in the dosage of recombinant SARS-CoV-2 protein subunit vaccine formulated with Alum and CpG 1018 showed safety parameters on the hematologic profile.]]>
