Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the novel virus that causes COVID-19, which was initially found in China and had spread rapidly worldwide. Patients with COVID-19 have had a wide range of respiratory symptoms which elderly patients with underlying diseases have a greater risk of developing acute respiratory distress syndrome and death. Currently, there is no vaccine and no specific treatment for COVID-19. Plasma donation from individuals who have recovered from the COVID-19 with a high level of SARS-CoV-2 antibodies is another potential adjunctive therapy for patients infected with SARS-CoV-2 National Blood Center (NBC) is responsible for providing patients with blood products for the treatment and producing human plasma-derived medicines. Therefore, this study aims to produce COVID-19 convalescent plasma (CCP) ready for adjunctive therapy and to study the factors involved antibodies to COVID-19 production in patients. Additionally, Hyperimmune globulin products are prepared from the convalescent plasma with a high titer of SARS-CoV-2 antibodies, called COVID-19 intramuscular immunoglobulin (CIMIG). This study started from April 2020 until July 2021 which 1,676 individuals recovered from COVID-19 registered via the pre-registration platform on the NBC website, of which 838 participants met the donor's criteria by phone and made an appointment for pre-screening. Then 451 participants were selected to participate in the CCP donation project, most of them are aged 31-45 years, and the proportion of males is higher than females. This project was divided into 2 phases according to the pandemic situation. For phase I, 155 individuals donated the CCP around 477 units, of which 348 units with neutralizing titer > 1:160 were used for adjunctive therapy 188 units and CIMIG production 160 units obtained 826 vials (NT titer of 1:5,120). For phase II, 296 individuals donated the CCP around 723 units, of which 668 units with SARS-CoV-2 Ig anti-RBD levels > 132 U/mL were used to transfuse the patients. A total of 1,712 doses of CCP from phase I and II were transported to hospitals and used to adjunctive therapy in 892 patients. The hospitals comprised 16 government hospitals and 33 private hospitals. For the factors related to the SARS-CoV-2 antibodies production, older people and symptom of pneumonia were significantly associated with the antibodies to SARS-CoV-2 level (p-value < 0.001). Besides, it also found that males were able to donate CCP longer than females (p-value <0.05). In addition, CIMIG was tested for efficacy and safety of clinical trial phase I in 10 participants. One had an adverse effect such as rash and low-grade fever, while low levels of SARS-CoV-2 antibodies were found to persist in all participants for approximately 3 weeks after injection. In summary, although the study limitations, our results have shown the association between SARS-CoV-2 antibodies levels and CCP donors characteristics, such as age, sex, and symptom of pneumonia, that were useful for further studies. Furthermore, this study documents Thailand's experience on the CCP production provided to transfused covid-19 patients and CIMIG production, which may be another way of covid-19 treatment in an emergency use setting. However, it needs further information from clinical research for standard treatment protocol.