is a monoclonal antibody which can prevent infection with respiratory syncytial virus (RSV).-Although palivizumab is recommended to infants at high risk of RSV-related complications in England, there is no national dataset that allows monitoring of access to palivizumab. What this study adds:-Using a novel data source of linked hospital admissions and pharmacy dispensing data, we found that a third of eligible children received palivizumab. -The odds of treatment were highest for babies born at <30 weeks' gestation, before the start of RSV season, and with multiple chronic conditions.

Objectives: Palivizumab is a monoclonal antibody which can prevent infection with respiratory syncytial virus (RSV). Due to its high cost, it is recommended for high-risk infants only. We aimed to determine the proportion of infants eligible for palivizumab treatment in England who receive at least one dose. Methods: We used the Hospital Treatment Insights database containing hospital admission records linked to hospital pharmacy dispensing data for 43/153 hospitals in England. Infants born between 2010 and 2016 were considered eligible for palivizumab if their medical records indicated chronic lung disease (CLD), congenital heart disease (CHD), or severe immunodeficiency (SCID), and they met additional criteria based on gestational age at birth and age at start of the RSV season (beginning of October). We calculated the proportion of infants who received at least one dose of palivizumab in their first RSV season, and modelled the odds of treatment according to multiple child characteristics using logistic regression models. Results: We identified 3,712 eligible children, of whom 2,479 (67%) had complete information on all risk factors. Palivizumab was prescribed to 832 of eligible children (34%). Being born at <30 weeks' gestation, aged <6 months at the start of RSV season, and having two or more of CLD, CHD or SCID were associated with higher odds of treatment. Conclusion: In England, palivizumab is not prescribed to the majority of children who are eligible to receive it. Doctors managing these infants might be unfamiliar with the eligibility criteria or are constrained by other considerations, such as cost.