title: Safety of DTaP-based combined immunization in very-low-birth-weight premature infants: frequent but mostly benign cardiorespiratory events.
abstract: OBJECTIVE
  To evaluate the safety of diphtheria-tetanus-acellular pertussis-inactivated polio-Haemophilus influenzae type B (DTaP-IPV-HIB) immunization in premature infants.
  
  
  METHODS
  Observational study of 78 very low birth weight premature infants (mean gestational age, 28+/-2 weeks; mean birth weight, 1045+/-357 g) given DTaP-IPV-HIB vaccine before hospital discharge. Apnea, bradycardia, oxygen requirements and saturation, feeding practice, and medical interventions were assessed before and after immunization. The results were analyzed by the severity of the clinical condition and the persistence of prematurity-associated symptoms.
  
  
  RESULTS
  Administration of DTaP-IPV-HIB elicited resurgence or increase in cardiorespiratory events in 47% of infants (15% had apnea, 21% had bradycardia, 42% of desaturations). Most vaccine-triggered events resolved spontaneously or after brief stimulation. The relative risk was 5- to 8-fold higher in infants with a severe clinical course or persistence of cardiorespiratory symptoms at the time of immunization. Bag-mask respiratory support was given to 5 of 78 infants, and O(2) requirements increased transiently in 4 of 21 infants with chronic lung disease, none requiring reventilation. Reintroduction of O(2) supplementation, interruption of active oral feeding, or postponing of hospital discharge was not required.
  
  
  CONCLUSIONS
  Cardiorespiratory events were frequently increased after DTaP-IPV-HIB immunization, requiring monitoring and appropriate intervention. However, these episodes did not have detrimental impact on the infants' clinical course. Timely immunization is warranted even in the most vulnerable preterm infants.
authors.affiliation: Division of Neonatology and Pediatric Intensive Care and WHO Collaborating Centre for Neonatal Vaccinology, Department of Pediatrics, University Hospital of Geneva, Switzerland.
authors.forename: Riccardo E
authors.initials: RE
authors.lastname: Pfister
authors.forename: Virginie
authors.initials: V
authors.lastname: Aeschbach
authors.forename: Viviane
authors.initials: V
authors.lastname: Niksic-Stuber
authors.forename: Blaise C
authors.initials: BC
authors.lastname: Martin
authors.forename: Claire-Anne
authors.initials: CA
authors.lastname: Siegrist
mesh_terms: D001049:Apnea / Q000139:chemically induced; D001919:Bradycardia / Q000139:chemically induced; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007252:Influenza Vaccines / Q000009:adverse effects*; D008297:Male; D010100:Oxygen / Q000097:blood; D011054:Poliovirus Vaccine, Inactivated / Q000009:adverse effects*; D012121:Respiration, Artificial / Q000706:statistics & numerical data
chemical_list: D015721:Diphtheria-Tetanus-Pertussis Vaccine; D007252:Influenza Vaccines; D011054:Poliovirus Vaccine, Inactivated; D010100:Oxygen