Neonatal Netw. 2024 Apr 1;43(2):105-115. doi: 10.1891/NN-2023-0056.
Respiratory syncytial virus (RSV) is the leading cause of hospitalization in infancy in the United States. Nearly all infants are infected by 2 years of age, with bronchiolitis requiring hospitalization often occurring in previously healthy children and long-term consequences of severe disease including delayed speech development and asthma. Incomplete passage of maternal immunity and a high degree of genetic variability within the virus contribute to morbidity and have also prevented successful neonatal vaccine development. Monoclonal antibodies reduce the risk of hospitalization from severe RSV disease, with palivizumab protecting high-risk newborns with comorbidities including chronic lung disease and congenital heart disease. Unfortunately, palivizumab is costly and requires monthly administration of up to five doses during the RSV season for optimal protection.Rapid advances in the past two decades have facilitated the identification of antibodies with broad neutralizing activity and allowed manipulation of their genetic code to extend half-life. These advances have culminated with nirsevimab, a monoclonal antibody targeting the Ø antigenic site on the RSV prefusion protein and protecting infants from severe disease for an entire 5-month season with a single dose. Four landmark randomized controlled trials, the first published in July 2020, have documented the efficacy and safety of nirsevimab in healthy late-preterm and term infants, healthy preterm infants, and high-risk preterm infants and those with congenital heart disease. Nirsevimab reduces the risk of RSV disease requiring medical attention (number needed to treat [NNT] 14-24) and hospitalization (NNT 33-63) with rare mild rash and injection site reactions. Consequently, the Centers for Disease Control and Prevention has recently recommended nirsevimab for all infants younger than 8 months of age entering or born during the RSV season and high-risk infants 8-19 months of age entering their second season. Implementing this novel therapy in this large population will require close multidisciplinary collaboration. Equitable distribution through minimizing barriers and maximizing uptake must be prioritized.
呼吸道合胞病毒（RSV）是美国婴儿住院的主要原因。几乎所有婴儿在 2 岁之前都被感染，需要住院治疗的细支气管炎经常发生在以前健康的儿童身上，严重疾病的长期后果包括语言发育迟缓、哮喘等。母体免疫不完全和病毒内高度遗传变异导致发病率高，也阻碍了成功的新生儿疫苗开发。单克隆抗体降低了严重 RSV 疾病住院的风险，帕利珠单抗保护患有慢性肺病和先天性心脏病等合并症的高危新生儿。不幸的是，帕利珠单抗成本高，需要在 RSV 季节每月注射多达五剂，以达到最佳保护效果。
在过去的二十年中，快速的进展促进了具有广泛中和活性的抗体的鉴定，并允许对其遗传密码进行操作以延长半衰期。这些进展的最终成果是 nirsevimab，一种针对 RSV 融合前蛋白 Ø 抗原位点的单克隆抗体，可为整个 5 个月的 RSV 季节提供保护，一次接种即可预防严重疾病。四项具有里程碑意义的随机对照试验，第一篇于 2020 年 7 月发表，证明了 nirsevimab 在健康晚期早产儿和足月儿、健康早产儿以及高危早产儿和先天性心脏病婴儿中的疗效和安全性。nirsevimab 降低了需要医疗关注（需要治疗的人数 [NNT] 14-24）和住院治疗（NNT 33-63）的 RSV 疾病的风险，不良反应罕见且轻微，为皮疹和注射部位反应。因此，疾病控制与预防中心最近建议在 RSV 季节进入或出生的所有 8 个月以下婴儿以及进入第二个 RSV 季节的 8-19 个月高危婴儿中使用 nirsevimab。在如此庞大的人群中实施这种新疗法需要密切的多学科合作。必须优先考虑通过减少障碍和最大限度地提高接受度来公平分配。
