After nirsevimab for infant respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) prevention became scarce, a recent study suggests that a new tool could be used to pinpoint the newborns who are most at risk of developing severe RSV LRTI. The research was presented at the ATS 2024 International Conference.Brittney M. Snyder, PhD, assistant professor at Vanderbilt University Medical Center, emphasized the importance of identifying infants at the highest risk of RSV-related illness in order to prevent it. She stated that their personalized risk prediction tool could be useful for allocating limited immunoprophylaxis resources and promoting RSV prevention among families with high-risk infants.
It is worth noting that over half of RSV lower respiratory tract infections (LRTIs) occur in healthy, full-term infants who are typically seen as low risk. Despite this perception, these infants are still at risk of developing severe cases.Intensive care unit-level care may be necessary for some infants who contract respiratory syncytial virus (RSV), and unfortunately, some may not survive the illness. The Centers for Disease Control & Prevention recommends early immunization with nirsevimab for all infants. However, in October 2023, there was a shortage of nirsevimab, leading the CDC to advise that it should only be given to high-risk infants who were not eligible for immunization with palivizumab. Both nirsevimab and palivizumab are monoclonal antibodies that can prevent RSV lower respiratory tract infection in newborns and young children. Nirsevimab is long-acting and only requires a single dose, while palivizumab is short-acting and needs to be injected monthly during RSV season. Dr. Snyder and colleagues conducted a population-based study on this topic.The researchers looked at infants, including children covered by the Tennessee Medicaid Program, who did not receive RSV immunoprophylaxis in their first year of life. They collected demographic and clinical information from health care encounters and connected birth certificates. A multivariable logistic regression model was developed to predict if these infants would develop severe RSV LRTI requiring ICU admission in their first year of life. The model included 19 demographic and clinical variables collected at or shortly after birth, such as prenatal smoking, delivery method, maternal age, and assisted breathing.Our goal was to create a personalized tool that could be used for all newborns by utilizing easily accessible birth and postnatal information to forecast the likelihood of severe RSV LRTI requiring ICU admission. This tool would be beneficial for prioritizing RSV prevention resources in situations where they may be limited,” explained Principal Investigator Tina V. Hartert, MD, MPH, from the Department of Medicine, Vanderbilt University Medical Center. During the course of the study, 429,365 infants were examined, with 713 of them experiencing severe RSV LRTI that necessitated ICU admission. The predictive tool demonstrated strong accuracy and was internally validated, indicating its effectiveness.The recent shortage of nirsevimab has improved, but there is still uncertainty about future shortages, according to PH, a professor of medicine and pediatrics at Vanderbilt University Medical Center. She believes that a new tool could help prioritize which infants should receive immunization during times when RSV prevention medicines are limited. The tool could also help identify infants at high risk for RSV infection, potentially persuading hesitant families to accept RSV immunoprophylaxis for their newborns. She also emphasized the importance of ensuring compatibility with nirsevimab.The researchers concluded that the tool they developed for maternal vaccination could be used in all infants, according to co-author Niek Achten, MD, postdoctoral fellow in pediatrics at Erasmus University Medical Center in Rotterdam, Netherlands. He emphasized the potential usefulness of the tool in countries with limited resources that need to prioritize vaccination for the highest risk infants, in addition to its use in the United States during times of limited availability. The authors also highlighted the need for further validation of the tool in external populations, as well as additional cost-effectiveness and decision curve analyses to ensure its optimal usefulness.
