Relevance. In the 21st century, humanity is faced with a pandemic unprecedented in recent history, which brought with it huge losses. All the efforts of world science are aimed at ensuring that the new coronavirus infection becomes vaccine-controlled. The Ministry of Health of Russia included vaccination against COVID-19 in the national calendar of preventive vaccinations. The most vulnerable and significant in the epidemiological chain are representatives of socially active, intensively communicating professions, including medical workers.Aims. The aim of the study was to assess the degree of severity of the post-vaccination immune response in employees of a medical organization vaccinated with the Gam-COVID-Vac preparation, who had not been ill and did not have antibodies before vaccination.Materials & Methods. The post-vaccination immunity of 80 vaccinated employees was assessed 42–62 days after the start of vaccination and 6 months later; assessment of the safety of vaccination with the Gam-Kovid-Vak vector vaccine; selection of optimal screening tests for laboratory examination of persons before the planned vaccination. The results of the PCR test for the detection of SARS-CoV-2 RNA (at the post-vaccination stage four times with an interval of 7 days) and the determination of M and G immunoglobulins to SARS-CoV-2 by the ELISA method were analyzed, postvaccination complications and reactions were assessed at different stages, monitoring the state of health and assessing the dynamics of the post-vaccination immune response.Results. A study conducted after 6 weeks showed the high immunological efficacy of the Gam-Covid-Vac vaccine; 100% of those vaccinated with one or two components of the vaccine had class G antibodies to SARS-CoV-2. Vaccination did not cause severe reactions during the observation period; among the side effects, general complaints and local pains at the injection site prevailed, which were of a short-term nature and did not have a significant impact on the health status and habitual rhythm of life of the participants. The resistance of those vaccinated to a new coronavirus infection decreased over time and amounted to 97.1% three months after vaccination and 95.6% after 6 months. COVID-19 disease in vaccinated employees (7.4% of cases of the number of vaccinated) was of moderate severity, did not lead to the development of pneumonia and respiratory failure, and did not require hospitalization.Conclusions. The results obtained allow us to conclude that the effectiveness of vaccination against COVID-19 is quite high. Revaccination is well tolerated clinically and «amplifies» the immune response when exposed to SARS-CoV-2. Immunization of employees of medical organizations is necessary, because. this focus group is the most epidemiologically potentially dangerous in terms of the spread of infection.

The issues of laboratory diagnostics have been relevant since the first days of the SARS-CoV-2 pandemic and play a key role in the fight against the spread of a new coronavirus infection. A direct method for the etiological diagnosis of the causative agent of COVID-19 is the detection of SARS-CoV-2 RNA using the nucleic acid amplification method. In the context of a pandemic and the mass appeal of patients for medical care, the issues of ensuring the quality of ongoing molecular biological studies at all stages (preanalytical, analytical, postanalytical) become the most relevant. the results and timing of the study not only affect the diagnosis and treatment tactics of a particular patient, but are also the basis for the introduction of anti-epidemic measures, the adoption of organizational measures. The study is to summarize the experience in creating an effective and reliable system for managing the quality of molecular biological research in a pandemic using the example of a federal budgetary healthcare institution. The experience of the laboratory of a federal healthcare institution in the context of the COVID-19 pandemic was analyzed, errors were analyzed at the preanalytical, analytical and postanalytical stages of PCR studies with the identification of quality criteria, the impact on which significantly leads to quality improvement. The quality control system for PCR studies is based on the development of regulatory documents and instructions for the patient and laboratory staff, registration of all documents in a single information system with access to information from all structural divisions, with the possibility of uploading data to the patient’s personal account on the institution’s website. Quality indicators of all stages of PCR studies and measures that significantly affect the quality of laboratory studies were identified; Measures have been identified to reduce the turnaround time of a PCR test: distribution of biomaterial flows, optimization of operators’ work, purchase of additional equipment, a patient feedback system, and an infection control information system. The obtained results make it possible to create a reliable quality control system, minimize the risk of obtaining erroneous research results, optimizing the work of the clinical diagnostic laboratory and increasing its productivity.