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Hypotonia and Lethargy as Potential Adverse Effect to Nirsevimab Administration in a Newborn Infant
Virginia María Velasco Molina1, María Nimo Mallo2, Samantha Tandrón Del Río1
1Neonatology Department (VVM, STR, PLO, GSG), Hospital General Universitario La Paz, Madrid, Spain.
Insights
Nirsevimab effectively reduces emergency visits for respiratory syncytial virus (RSV) in infants. A case study noted transient hypotonia in a newborn post-nirsevimab, highlighting the need for ongoing safety monitoring in neonates.
Area of Science:
- Pediatrics
- Immunology
- Neonatology
Background:
- Respiratory syncytial virus (RSV) is a leading cause of infant respiratory infections.
- Nirsevimab immunoprophylaxis significantly lowers RSV-related hospitalizations and emergency department visits.
- Clinical trials indicate nirsevimab is generally well-tolerated with mild adverse events.
Purpose of the Study:
- To report a case of adverse events following nirsevimab administration in a neonate.
- To assess the clinical presentation and diagnostic workup of a neonate experiencing hypotonia post-nirsevimab.
- To emphasize the importance of continued pharmacovigilance for new immunoprophylactic agents.
Main Methods:
- Case report of a 13-day-old female neonate presenting with hypotonia and unresponsiveness.
- Clinical evaluation including physical examination, cerebral function monitoring, and electroencephalogram (EEG).
- Review of nirsevimab's known safety profile and clinical trial data.
Main Results:
- The neonate exhibited mild axial hypotonia that resolved spontaneously within 48 hours.
- Cerebral function monitoring and EEG showed no evidence of seizures or abnormal brain activity.
- All diagnostic investigations yielded normal results, with nirsevimab administration preceding symptom onset.
Conclusions:
- A potential association between nirsevimab and transient hypotonia in a neonate was suggested.
- While nirsevimab is recommended for RSV prevention, continued monitoring for side effects in neonates is crucial.
- This case underscores the need for vigilance regarding nirsevimab's safety profile in the youngest infants.
Abstract:
Respiratory syncytial virus (RSV) is one of the most common causes of acute lower respiratory tract infections in children. Immunization with nirsevimab has had a positive impact in reducing the number of emergency department (ED) visits for RSV. Clinical trials have shown that most adverse events associated with nirsevimab administration were mild, with no significant difference compared with placebo. We report on a 13-day-old female newborn who was brought into the ED because of hypotonia and unresponsiveness after administration of nirsevimab. During the 48-hour hospital stay, the only relevant clinical finding was mild axial hypotonia, which gradually resolved without treatment. A cerebral function monitor showed a continuous normal voltage tracing with no signs of seizures, and a complete electroencephalogram revealed normal background activity. Given that all the investigations were normal and the main event preceding the events was the administration of immunoprophylaxis with nirsevimab, a possible association between the clinical symptoms and the medication was suggested. Although there is robust evidence to recommend nirsevimab for reducing hospitalizations, we must bear in mind that, as a relatively new drug, we believe it is essential to emphasize continued monitoring of side effects, particularly in neonates.
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