SARS-CoV-2 pathophysiology and post-vaccination severity: a systematic review

Currently, COVID-19 is still striking after 4 years of prevalence, with millions of cases and thousands of fatalities being recorded every month. The virus can impact other major organ systems, including the gastrointestinal tract (GIT), cardiovascular, central nervous system, renal, and hepatobiliary systems. The resulting organ dysfunction from SARS-CoV-2 may be attributed to one or a combination of mechanisms, such as direct viral toxicity, disruptions in the renin-angiotensin-aldosterone system (RAAS), thrombosis, immune dysregulation, and ischemic injury due to vasculitis. SARS-CoV-2 vaccines effectively reduce the severity of the disease, hospitalizations, and mortality. As of October 2024, 13.58 billion vaccine doses have been administered, with an average of 6959 daily doses. Also, the boosters are given after the primary immunization in a homologous and heterologous manner. The vaccines imposed severe potential health side effects such as clotting or obstruction of blood vessels termed arterial or venous thrombosis, autoimmune damage of nerve cells (Guillain-Barré syndrome; GBS), intense activation of coagulation system (vaccine-induced thrombotic thrombocytopenia), acute ischemic stroke (AIS) and cerebral venous sinus thrombosis (CVST), myocarditis, pericarditis, and glomerular disease. Overall, it is essential to highlight that the significant benefits of COVID-19 vaccination far outweigh the low risk of conditions. mRNA-based vaccine technology has emerged as a rapidly deployable vaccine candidate and a viable alternative to existing vaccines. It has a very low probability of adverse health effects, confirmed by data represented by Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Vaccine Adverse Event Reporting System (VAERS), Yellow card approved under CDC, WHO.