The article elaborates on the principles and modern methodology of evaluating vaccine safety, efficacy and effectiveness. The main parameters and criteria of successful immunization are described in plain and concise language. Special attention is paid to the analysis of clinical and epidemiological aspects of vaccination against Covid-19. The article provides the most recent epidemiological statistics on this disease. A report of the efficacy and safety of the BNT162b2 vaccine is given as an example.

Nonalcoholic fatty liver disease (NAFLD) is a disease which etiology is related to various metabolic, ethnic, genetic and even ecologic factors. Complexity of etiology and multiply pathogenesis ways, leading eventually to the lipid droplets appearance in hepatocytes, infl ammation process and parenchyma fi brosis in liver, and also frequent cardiometabolic comorbidities, together make diffi cult risks stratifi cation and prognosis evaluation in NAFLD patients. Another matter is a question of NAFLD therapy, since unifi ed pharmacotherapy approaches are not yet adopted worldwide, and lifestyle modifi cation being accepted as an eff ective therapeutic approach, is not followed by patients in real world setting. Current review is dedicated to the consideration of NAFLD diagnostics, its risk of progression and existing therapeutical capabilities.