Background & objective: SARS-CoV-2 virus caused acute respiratory illness called COVID-19 with rising case mortality rates. One of the preventive measures to arrest the spread of a contagious disease is the use of vaccines. We assessed the effectiveness of the inactivated vaccine (Coronavac) through three inflammatory parameters e.g., total lymphocyte count, neutrophil-lymphocyte ratio, and C-reactive protein (CRP), in severe COVID-19 patients. Methodology: This study was an observational study with a retrospective cross-sectional design. The study was conducted in the Intensive Care Unit (ICU) of Hasan Sadikin Hospital Bandung, from January 2021 to December 2021. The data of total lymphocyte count, neutrophil-lymphocyte ratio, and C-reactive protein, was collected retrospectively from the medical record documents of 54 patients of COVID-19. The assessment was performed on severe COVID-19 subjects on the 7th day of illness. Data normality test was done using the Shapiro Wilk test. Study data were not normally distributed, and statistical analyses were performed using the Mann-Whitney test for numerical data and the Chi-Square test for categorical data. Results: There were significant differences in inflammation parameters, e.g., total lymphocyte count, neutrophil-lymphocyte ratio, and CRP, between the two groups (P < 0.0001) and the subject outcome between two groups (P < 0.0001). Total lymphocyte count in severe vaccinated COVID-19 patients was higher than in non-vaccinated patients, while neutrophil-lymphocyte ratio and CRP were lower in vaccinated subjects. Mortality was also lower in the vaccinated patients compared to unvaccinated patients. Conclusion: The inactivated vaccine (Coronavac) effectively reduces the mortality rate of severe COVID-19 patients based on inflammatory parameters including total lymphocyte count, neutrophil-lymphocyte ratio, and C-reactive protein. Abbreviations: ACE: Angiotensin Converting Enzyme; ARB: Angiotensin Receptor Blocker; ARDS: Acute Respiratory Distress Syndrome; BMI: Body Mass Index; CFR: Case Fatality Rate; COVID-19: Coronaviruses Disease 2019; CRP: C-Reactive Protein; IL: Interleukin; NLR: Neutrophil Lymphocyte Ratio; SPSS: Statistical Product Service Solution; TLC: Total Lymphocyte Count; TNF: Tumor Necrosis Factor; VEGF: Vascular Endothelial Growth Factor Citation: Sudjud RW, Zulfariansyah A, Ardiana K. Comparison of total lymphocytes, neutrophils to lymphocytes ratio, and C-reactive protein in vaccinated and unvaccinated severe COVID-19 patients. Anaesth. pain intensive care 2022;26(5):656-662; DOI: 10.35975/apic.v26i5.2018