Mass vaccination of shift workers at a large construction site as a measure to prevent socially significant infections

Relevance . Biological emergencies caused by infectious agents are characterized by acute onset, rapid spread, and involvement of large populations in the epidemic process. Epidemics develop especially quickly in large, densely populated areas sharing the same living, eating, and working conditions, which is typical of shift workers involved in major construction sites. Vaccination remains the most effective method to prevent socially significant infectious diseases and avoid epidemic outbreaks. The objective is to analyze the experience of mass vaccination organization and management among shift workers at a large construction to prevent socially significant infectious diseases. Methods . The focus of the study is immunoprophylaxis of socially significant infections at a large construction site in the Far Eastern region of Russia; the study subjects are shift workers residing in the Russian Federation, neighboring, or far–fetched countries. For the study period from January 2020 through December 2024, the daily average number of on–site workers was (27,182 ± 2,625) (ranging from 12,508 to 39,120 depending on the phase of work). During their on–site stay, workers were accommodated in temporary camps equipped with dormitories made from modular buildings; meals was served in camp canteens, and transportation to and from the work locations was provided by company buses. Vaccines represented domestic formulations used for immunoprophylaxis of the following socially significant infections: influenza (“Ultrix Quadri”, “Sovigripp”, “Grippol Plus”), pneumococcal infection (“Prevenar–13”), coronavirus infection (vector vaccines “Sputnik V”, “Sputnik Lite”), measles (live–attenuated) and tick–borne viral encephalitis (“EnceVir”, “Klesch–E–Vac”). All vaccines administered in accordance with the official guidelines. The effectiveness of vaccination organization and management was assessed using logical analysis, expert evaluation, and epidemiological research. Statistical data processing was carried out using generally accepted methods of statistical analysis. Results and discussion . The retrospective analysis of mass vaccination measures among shift workers of a large construction site against socially significant infections were obtained. Vaccination of shift workers was carried out in a designated vaccination room, a temporary vaccination station of the on–site infectious disease hospital, as well as in mobile vaccination stations deployed in temporary shift camps accommodating construction workers. The paper elaborates the layout of vaccination infrastructure, logistics, and information on the total number of preventive vaccinations performed at the site in 2020–2024. In fall 2020, before Covid–19 vaccines were available, mass influenza vaccination was administered, covering 80.7 % of the total number of workers staying at the construction site, thus allowing to prevent an outbreak of influenza and acute respiratory viral infections amid the ongoing epidemic of a new coronavirus infection. Thereafter, influenza vaccination was conducted annually, covering at least 60–65 % of the total number of project employees. Vaccination against pneumococcal infection was conducted jointly with influenza vaccination, primarily in managers, engineers, and technical staff, as well as in high–risk individuals. These efforts prevented the development of severe invasive pneumococcal infection and significantly reduced the incidence of non–invasive clinical cases. The estimated data on the cost–effectiveness of influenza and pneumococcal vaccination was confirmed by decreased incidence of influenza, acute respiratory viral infections, and pneumonia. Mass vaccination against COVID–19 was carried out in 2021 and 2022, eventually allowing to completely stabilize the epidemiological situation at the site and minimize the incidence of a new coronavirus infection. Due to the emerging threat of imported measles, a large–scale (more than 16,000 shift workers) preventive vaccination against measles was conducted in winter–spring 2020. In 2023–2024, measles vaccination was conducted mainly for epidemic indications. The annual vaccination against tick–borne viral encephalitis allowed to eliminate clinical cases of the disease among project employees, despite a significant number of tick bites, including virus–positive cases. Overall, over 130,000 immunizations against socially significant infections were administered during 2020–2024. Conclusion . Mass vaccination of shift workers against most critical socially significant infections allowed to prevent epidemic outbreaks of infectious diseases and enabled timely and prompt progress of a large–scale construction project.