The effect of immunoprophylaxis of respiratory syncytial virus infection in children at risk of severe course and its completion on the frequency of repeated episodes of bronchial obstruction, community-acquired pneumonia in early childhood

Timely immunoprophylaxis of respiratory syncytial virus (RSV) infection aimed at reducing the risks of severe disease during infancy may influence the incidence of subsequent respiratory diseases in this cohort of children at an early age. Objective: to evaluate the impact of immunoprophylaxis of RSV infection carried out in the first year of life in children at risk of severe course, and its completion on the frequency of repeated episodes (≥3 times a year) of bronchial obstruction, community-acquired pneumonia at an early age. Materials and methods. A prospective case-control study was conducted from 2020 to 2024. 247 children aged 1–3 years were observed: the case group consisted of 150 children who received immunization courses against RSV infection, the control group – 97 children who did not receive immunoprophylaxis. The passive immunization course included 3–5 injections of the monoclonal antibody to the RSV F protein palivizumab from October 1 to April 1 at a dose of 15 mg/kg of body weight. The frequency of respiratory infections was also compared in children who received 1–2 (n=75, “incomplete immunization course” group) and 3–5 (n=150, “cases” group, “completed immunization course”) injections of the drug. The mean value and standard deviation (M) were calculated, as well as odds ratio (OR) indicators with 95% confidence interval (CI). Results: Children immunized in the first year of life, compared with children without immunization, had a lower risk of recurrent (≥3 times per year) episodes of bronchial obstruction (OR = 4,33 95% CI [2,44–7,70]) and community-acquired pneumonia (OR = 3,38 95% CI [1,86–6,14]) in early life. A completed course of immunization (3-5 injections of monoclonal antibodies) compared with an incomplete course (1–2 injections) significantly reduced the risk of repeated (≥3 times a year) episodes of bronchial obstruction (OR=2,2 95% CI [1,27–5,00]). Conclusion: Immunoprophylaxis of RSV infection in children at risk significantly reduces the risk of episodes of bronchial obstruction and community-acquired pneumonia at the age of 1-3 years.