Routine immunizations and adverse events in infants with single-ventricle physiology

Infants with single-ventricle congenital heart defects are at risk of sudden unexpected death. In an effort to decrease the risk of sudden death, some centers have advocated that routine immunizations be deferred in this population. However, it is not known if an association exists between immunizations and adverse events.

The present study examined the relationship of routine immunizations with adverse events, which were defined as sudden death or hospital readmission. The diphtheria-tetanus-acellular pertussis (DTaP) vaccine was considered in the analysis. The patient population consisted of infants younger than 9 months old who resided locally and had not yet undergone bidirectional cavopulmonary anastomosis (BCPA). Immunization data were obtained from a mandatory statewide database.

During a 35-month period, 137 patients with single-ventricle physiology were discharged home after neonatal surgery or directly from the newborn nursery. Hypoplastic left heart syndrome (HLHS) was the diagnosis in 58 patients (42%) and was the most common. In the entire cohort, there were four sudden deaths (3%), and 53 patients (38%) had at least one interval hospital admission. Immunization within 48 hours was not associated with adverse events (odds ratio, 1.48; 95% confidence interval, 0.73 to 2.90; p = 0.31). No sudden death events occurred within 48 hours of immunization.

No association could be identified between routine immunizations and adverse events in infants with single-ventricle physiology. As such, the proposal to alter the immunization regimen in this population does not appear justified.