Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 16 1 2024 02 12 124 131 Nazanin Joudaki Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran Samireh Ghafouri Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Kowsar Bavarsad Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Farbod Farhadi epartment of Surgery, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Marzieh Abbasi Nasab Thalassemia and Hemoglobinopathy Research Center, Research Institute of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Sara Afzalzadeh Department of Infectios Disease, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Hamidreza Moradzadegan Thalassemia and Hemoglobinopathy Research Center, Research Institute of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Roya Salehi Kahyesh Thalassemia and Hemoglobinopathy Research Center, Research Institute of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2023 03 24 2023 11 17 Background and Objectives: This study aimed to compare the production of antibodies in three different groups of patients with COVID-19. These groups included patients with pulmonary and cerebral symptoms, as well as those with mild symptoms. Materials and Methods: Blood samples were collected from 80 patients admitted to COVID-19-specific hospitals. The patients had various forms of SARS-CoV-2 disease, including those with pulmonary symptoms, brain involvement, and those with positive PCR test results but mild symptoms. The enzyme-linked immunosorbent assay (ELISA) technique was used to determine the levels of IgM and IgG antibody titers. Results: The levels of IgM and IgG antibody production differed significantly between groups of patients experiencing pulmonary symptoms and cerebral symptoms, with mild symptom patients also showing differences (P=0.0068), (P=0.0487), (P<0.0001), and (P=0.0120), respectively. Furthermore, there was no significant relationship between IgM antibody secretion and age or pulmonary involvement (P=0.1959). However, there was a direct and significant relationship between age and brain involvement (P=0.0317). Conclusion: The findings of this study revealed that the risk of central nervous system involvement increases with age and that older people have lower antibody levels than younger people. Consequently, strengthening the immune systems of people over the age of 78 during this pandemic through vaccination and nutrition is very effective in reducing mortality in this age group. https://ijm.tums.ac.ir/index.php/ijm/article/view/4164 https://ijm.tums.ac.ir/index.php/ijm/article/download/4164/1645