COVID-19: sinalização celular, resposta imune e vacinas

Abstract

Several studies have investigated the mechanisms of cellular signaling, immune response, and vaccine development related to SARS-CoV-2, the virus responsible for COVID-19. The present study aims to explore how these mechanisms influence immunization processes and the development of effective vaccines against COVID-19. The study focuses on three specific objectives: understanding the cellular signaling mechanism of SARS-CoV-2, analyzing the immunological response to the virus, and examining the development process of vaccines. A comprehensive bibliographic review was conducted, sourcing information from national and international scientific platforms. The review highlights the critical role of the spike protein in SARS-CoV-2's entry into host cells via the ACE2 receptor, initiating a cascade of intracellular signaling pathways. These pathways are pivotal in viral replication and the host's inflammatory response. The immune response to SARS-CoV-2 involves both innate and adaptive immunity. Initial responses include the activation of PRRs like TLRs, which recognize viral RNA and trigger cytokine production, including type I interferons. The adaptive response is marked by the activation of B cells, which produce neutralizing antibodies, and T cells, which help eliminate infected cells and coordinate antibody production. The balance between these responses determines disease severity and long-term immunity. The development of COVID-19 vaccines has utilized various platforms, including mRNA vaccines (Pfizer-BioNTech, Moderna), viral vector vaccines (AstraZeneca, Johnson & Johnson), protein subunit vaccines (Novavax), and inactivated virus vaccines (Sinovac). These vaccines aim to induce robust immune responses by presenting antigens that mimic the SARS-CoV-2 spike protein. Booster doses have been effective in enhancing immunity against emerging variants by increasing antibody titers and strengthening memory B and T cell responses, thereby providing sustained protection against infection and severe disease. In conclusion, understanding the interplay between SARS-CoV-2 cellular signaling and the immune response is crucial for optimizing vaccine development. Ongoing research and adaptation are essential to address the challenges posed by viral variants, ensuring effective and long-lasting immunization against COVID-19.