EVALUATION OF THE IMPACT OF CYTOMEGALOVIRUS (CMV) REACTIVATION ON THE SYSTEMIC IMMUNE/INFLAMMATORY RESPONSE OF OLDER ADULTS VACCINATED FOR RESPIRATORY DISEASES

• Grant number: 23/12882-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2024
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Immunology - Applied Immunology
• Principal Investigator: André Luis Lacerda Bachi
• Grantee: Ana Paula Costa Mugnaini
• Host Institution: Universidade de Santo Amaro (UNISA). São Paulo , SP, Brazil

Abstract

Although we are no longer in a COVID-19 pandemic, it is known that the older adult population was not only one of the most affected populations but also the one that accounted for the highest number of deaths from this disease. Studies suggest that the increased rate of infection, severity, and lethality caused by SARS-CoV-2 viruses in the aged population is closely associated with both the occurrence of immunosenescence and the "inflammaging" phenomenon. In this sense, it has been proposed that the reactivation of infection by cytomegalovirus (CMV), a herpes virus, can favor the development of immunosenescence, as this could be an important triggering factor of "inflammaging". It is worth highlighting that it is broadly known that immunosenescence and "inflammaging" negatively impact the vaccine responses of older adults. Objective: Based on these pieces of information, in this study, we aimed to investigate the impact of CMV seropositivity and reactivation on systemic immune/inflammatory responses in older adults vaccinated for COVID-19. Methods: Eighty-two aged individuals of both sexes, aged between 60 and 85 years, were invited to participate in the study, and blood samples from these participants were obtained at two distinct moments: before and 30 days after administration of the fourth dose of the vaccine for COVID-19. Serum and peripheral blood mononuclear cells (PBMC) were obtained from these blood samples, which are properly stored at -800C or liquid nitrogen, respectively, on the premises of the UNISA Research Laboratory (URC). In stored serum samples, not only seropositivity for CMV will be assessed, but also systemic concentrations of IgA and IgG specific to SARS-CoV-2 antigens and pro- and anti-inflammatory profile cytokines. Besides, CMV reactivation will be evaluated at PBMC.