Anti-SARS-CoV-2 antibody among SARS-CoV-2 vaccinated vs post-infected blood donors in a tertiary hospital, Bangkok, Thailand.

SARS-CoV-2 virus infection has imposed a significant healthcare burden globally. To contain its spread and decrease infection-related mortality, several vaccines have been deployed worldwide in the past 3 years. We conducted a cross-sectional seroprevalence study to assess the immune response against the virus among blood donors at a tertiary care hospital, Bangkok, Thailand. From December 2021 to March 2022, total of 1,520 participants were enrolled, and their past history of SARS-CoV-2 infection and vaccination was recorded. Two serology test, namely, quantitative IgG spike protein (IgGSP) and qualitative IgG nucleocapsid antibody (IgGNC) were performed. The median age of study participants was 40 years (IQR 30-48) and 833 (54.8%) were men. Vaccine uptake was reported in 1,500 donors (98.7%) and 84 (5.5%) reported the past infection history. IgGNC was detected in 46/84 donors with the past infection history (54.8%) and in 36 out of the rest 1,436 (2.5%) with no past history. IgGSP positivity was observed in 1484 donors (97.6%). When compared to unvaccinated donors (n = 20), IgGSP level was higher in the donors who had received one vaccine dose (p< 0.001) and these antibody levels increased significantly among those with 3rd and 4th vaccine doses. Factors associated with low IgGSP (lowest quartile) by multivariate analysis included: no past infection history, homologous vaccination, < 3 vaccine doses, and > 90 days duration since last vaccination. In conclusion, vaccine uptake among our study donors was high (98.7%) and IgGSP antibody was observed in nearly all the vaccinated donors (97.6%). Previous SARS-CoV-2 infection, use of heterologous vaccination, vaccines ≥ 3 doses, and duration of the last vaccination >90 days affected IgGSP levels. Use of serological assays were found beneficial in the evaluation and differentiation of immune response to vaccination, and natural infection including the identification of previous asymptomatic infections.

Characteristics, outcomes, and risk factors for in-hospital mortality of COVID-19 patients: A retrospective study in Thailand.

Introduction: Data on the characteristics and outcomes of patients hospitalized for Coronavirus Disease 2019 (COVID-19) in Thailand are limited. Objective: To determine characteristics and outcomes and identify risk factors for hospital mortality for hospitalized patients with COVID-19. Methods: We retrospectively reviewed the medical records of patients who had COVID-19 infection and were admitted to the cohort ward or ICUs at Siriraj Hospital between January 2020 and December 2021. Results: Of the 2,430 patients included in this study, 229 (9.4%) died; the mean age was 54 years, 40% were men, 81% had at least one comorbidity, and 13% required intensive care unit (ICU). Favipiravir (86%) was the main antiviral treatment. Corticosteroids and rescue anti-inflammatory therapy were used in 74 and 6%, respectively. Admission to the ICU was the only factor associated with reduced mortality [odds ratio (OR) 0.01, 95% confidence interval (CI) 0.01-0.05, P < 0.001], whereas older age (OR 14.3, 95%CI 5.76-35.54, P < 0.001), high flow nasal cannula (HFNC; OR 9.2, 95% CI 3.9-21.6, P < 0.001), mechanical ventilation (OR 269.39, 95%CI 3.6-2173.63, P < 0.001), septic shock (OR 7.79, 95%CI, 2.01-30.18, P = 0.003), and hydrocortisone treatment (OR 27.01, 95%CI 5.29-138.31, P < 0.001) were factors associated with in-hospital mortality. Conclusion: The overall mortality of hospitalized patients with COVID-19 was 9%. The only factor associated with reduced mortality was admission to the ICU. Therefore, appropriate selection of patients for admission to the ICU, strategies to limit disease progression and prevent intubation, and early detection and prompt treatment of nosocomial infection can improve survival in these patients.