Regional impact of prophylaxis with the monoclonal antibody palivizumab on ospitalizations from respiratory syncytial virus in infants

2001 Swiss Medical Weekly  
RSV is the leading cause of lower respiratory tract infections in infants. Up to 70% are infected during the first year of life [1] . Of these, 20% have evidence of lower respiratory tract disease, 2% are hospitalised, and 0.1% die from RSV infection [2] . Risk factors associated with increased RSV hospitalisation rates include prematurity (10-25%) [1, 3] , CLD (15-45%) [1, 3] , and congenital heart disease (15-25%) [4], but there is regional variability in both the severity of RSV disease and
more » ... of RSV disease and hospitali-sation policies [5] [6] [7] [8] [9] . In healthy infants born at term, the severity of RSV infection is inversely correlated with age [1]. Hence, RSV infection is one of the major infectious diseases during the first year of life and effective means for its prevention are needed. Active immunisation and antiviral therapy face obstacles that will not be resolved in the near future [10] . Passive immunisation with anti-RSV antibodies, however, has been shown to prevent RSV infection both in laboratory animals [11] and in children [12, 13] . This observation led to the development of palivizumab, a neutralising, humanised, monoclonal, IgG 1 antibody directed against the F glycoprotein of RSV [14] . The efficacy of palivizumab in reducing the hospitalisation rate for RSV infection in high risk infants has been Questions: Palivizumab is approved in Switzerland for prevention of hospitalisation for RSV infection in children with one of the following risk factors: (1) history of prematurity ≤ 35 weeks and age ≤ 6 months or (2) chronic lung disease and age ≤ 1 year. Regional data on the expected effectiveness of this monoclonal antibody are not available. Methods: (1) Retrospective, descriptive, singlesite study on the characteristics of RSV hospitalisations during two consecutive seasons. (2) Extrapolation of data to generate population-based estimates on the impact of palivizumab if used according to the approved indications. Results: Of 242 RSV hospitalisations, 216 (89.3%) and 26 (10.7%) occurred in children without and with risk factors, respectively. Patients without and with risk factors had similar clinical courses with respect to ICU admission rate (11.6 vs. 11.5%) and rate of mechanical ventilation (3.2 vs. 3.8%). Of a total of 28 ICU admissions, 13 (46%) occurred among infants aged ≤ 1 month without risk factors. Former premature infants were significantly older than patients with longer gestation (median age 7.5 vs. 3.7 months, p = 0.026). Applying the approved age criteria would have excluded 10 of 26 patients (38.5%) from eligibility for palivizumab. During the
doi:10.4414/smw.2001.09681 fatcat:vgf6rwevlbftbmxo2wrobncg3i