Young children with neuromuscular disease are vulnerable to respiratory viruses

Influenza gets a lot of attention each winter, but respiratory syncytial virus (RSV) and other respiratory viruses have as much or more impact on pediatric populations, particularly certain high-risk groups. But currently there are no vaccines for noninfluenza respiratory viruses. That said, several are under development, for RSV and parainfluenza.

Dr. Christopher J. Harrison

Which groups are likely to get the most benefit from these newer vaccines?

We all are aware of the extra vulnerability to respiratory viruses (RSV being the most frequent) in premature infants, those with chronic lung disease, or those with congenital heart syndromes; such vulnerable patients are not infrequently seen in routine practice. But patients from another less frequent category – those with neuromuscular disease – may be even more vulnerable and may benefit more from new vaccines. A recent report shined a brighter light on such a group.

Real-world data from a nationwide Canadian surveillance system (CARESS) was used to analyze relative risks of categories of young children who are thought to be vulnerable to respiratory viruses, with a particular focus on those with neuromuscular disease. The CARESS investigators analyzed 12 years’ data on respiratory hospitalizations from among palivizumab-prophylaxed patients (including specific data on RSV when patients were tested for RSV per standard of care).¹ Unfortunately, RSV testing was not universal despite hospitalization, so the true incidence of RSV-specific hospitalizations was likely underestimated.

Nevertheless, more than 25,000 children from 2005 through 2017 were grouped into three categories of palivizumab-prophylaxed high-risk children: standard indications (SI), n = 20,335; chronic medical conditions (CMD), n = 4,063; and neuromuscular disease (NMD), n = 605. This study is notable for having a relatively large number of neuromuscular disease subjects. Two-thirds of each group were fully palivizumab adherent.

The SI group included the standard American Academy of Pediatrics–recommended groups, such as premature infants, congenital heart disease, etc.

The CMD group included conditions that lead clinicians to use palivizumab off label, such as cystic fibrosis, congenital airway anomalies, immunodeficiency, and pulmonary disorders.

The NMD participants were subdivided into two groups. Group 1 comprised general hypotonic neuromuscular diseases such as hypoxic-ischemic encephalopathy, Prader-Willi syndrome, chromosomal disorders, and migration/demyelinating diseases. Group 2 included more severe infantile neuromuscular disorders, such as spinal muscular atrophy, myotonic dystrophy, centronuclear and nemaline myopathy, mitochondrial and glycogen storage myopathies, or arthrogryposis.