One-year observational study of palivizumab prophylaxis on infants at risk for respiratory syncytial virus infection in Latin America

Objective: This study aims to describe real world palivizumab use and effectiveness in high-risk Latin American infants and young children. Method: Prospective, multicenter observational study with infants at risk for severe RSV infection who received palivizumab according to routine clinical practice. Subjects were followed for one year with monthly visits after the first dose of palivizumab. An infant was considered adherent if receiving all the expected injections or five or fewer injections within appropriate inter-dose intervals. Annual incidence rates and risk factors of lower respiratory tract infection (LRTI) hospitalization were determined through Poisson regression models (α = 0.05). Results: The study enrolled 458 children from seven countries in Latin America, from February 2011 to September 2012. The majority (98%) were born <36 weeks gestation. Overall, patients received 83.7% of their expected injections and 86.7% completed one year of follow-up. Of the 61 LRTI hospitalizations, 12 episodes were due to RSV infection. The RSV-associated hospitalization rate was 2.9 per 100 patient-years. Bronchopulmonary dysplasia was identified as an independent risk factor for LRTI hospitalization. A total of 1165 adverse events were recorded during one year of follow-up. One hundred and two patients (22.3%) had a total of 135 serious adverse events, but no events were considered to be related to palivizumab. Conclusions: The rate of RSV hospitalization in high-risk infants in Latin America was low and aligned with those observed in randomized control trials and observational studies. Palivizumab prophylaxis appeared effective and had a good safety profile in this population. Resumo: Objetivo: Este estudo visa descrever o uso e a eficácia do palivizumabe no mundo real em neonatos e jovens crianças de alto risco latino-americanas. Método: Estudo observacional prospectivo multicêntrico com neonatos em risco devido a infecção grave por VSR que receberam palivizumabe de acordo com a prática clínica de rotina. Os indivíduos foram acompanhados por um ano, com visitas mensais após a primeira dose de palivizumabe. Um neonato foi considerado adepto se recebeu todas as injeções esperadas ou ≤5 injeções nos intervalos entre doses adequados. As taxas de incidência anuais e os fatores de risco de internação por infecção do trato respiratório inferior (ITRI) foram determinados por meio dos modelos de regressão de Poisson (α = 0,05). Resultados: O estudo inscreveu 458 crianças de sete países da América Latina, de fevereiro de 2011 a setembro de 2012. A maioria (98%) nasceu com