ABSTRACT
Since the start of the pandemic, the number of cases has been increased rapidly. Due to asymptomatic and mild cases and restricted testing in many geographic locations, the overall number of actual COVID-19 cases is likely significantly higher than the number of verified cases. Several COVID-19-related comorbid diseases impair immune system function, which has an impact on COVID-19 responsiveness. So, we evaluated the immune response to SARS-CoV-2 after the third wave of COVID-19 and assessed the effect of comorbid diseases on this immune response. The current cross-sectional study was conducted in August 2021 after the third wave of COVID-19. The study included 287 participants. All participants were asked about their epidemiological data, comorbid diseases, data suggesting COVID-19 infection, and precautions measures to minimize the exposure to the disease. Of the 278 participants, 50% had a positive IgG response to COVID-19. Regarding comorbid diseases, the IgG antibody titer was significantly lower in patients with chronic kidney diseases (CKD) on dialysis, ischemic heart disease, and chronic obstructive lung diseases than other participants (p= 0.01, p= 0.02, p= 0.005, respectively). Neither precaution measures nor comorbid diseases had a role in risk factors of COVID-19 infections in our participants. In conclusion, high seroprevalence (50%) of SARS-CoV-2 IgG antibody after the third wave of COVID-19 was observed in the current study. Comorbid conditions as hypertension, chronic cardiac diseases, chronic chest problems, and CKD on dialysis could decrease the immune response against COVID-19 infection. Copyright© by the Egyptian Association of Immunologists.