Respiratory Syncytial Virus Immunoprophylaxis with Palivizumab: 12-Year Observational Study of Usage and Outcomes in Canada

Am J Perinatol. 2022 Nov;39(15):1668-1677. doi: 10.1055/s-0041-1725146. Epub 2021 Mar 3.

Abstract

Objective: This study aimed to evaluate palivizumab (PVZ) use, trends in indications, and outcomes of respiratory illness hospitalizations (RIH) and respiratory syncytial virus hospitalizations (RSVH).

Study design: It involves a large, Canadian prospective (2005-2017) observational multicenter study of children at high risk for RSV infection.

Results: A total of 25,003 infants (56.3% male) were enrolled at 32 sites; 109,579 PVZ injections were administered. Indications included: prematurity (63.3%); "miscellaneous" (17.8%); hemodynamically significant congenital heart disease (10.5%); bronchopulmonary dysplasia/chronic lung disease (8.4%). The "miscellaneous" group increased over time (4.4% in 2005-2006 to 22.5% in 2016-2017) and included: trisomy 21, airway anomalies, pulmonary disorders, cystic fibrosis, neurological impairments, immunocompromised, cardiac aged >2 years, multiple conditions, and a residual "unclassified" group. Adherence measured by expected versus actual doses plus correct interdose interval was 64.7%. A total of 2,054 RIH occurred (6.9%); 198 (9.6%) required intubation. Three hundred thirty-seven hospitalized children were RSV-positive (overall RSVH 1.6%). Risk factors for RSVH included having siblings, attending daycare, family history of atopy, smoking exposure, and crowded household. Infants with 5 risk factors were 9.0 times (95% CI or confidence interval 4.4-18.2; p < 0.0005) more likely to have RSVH than infants without risk factors. Three adverse events occurred; none were fatal.

Conclusion: Results are relevant to both clinicians and decision-makers. We confirmed the safety of PVZ. Use of PVZ increased steadily for children with miscellaneous conditions and medical complexity. Medical and social factors pose a risk for severe RIH and RSVH with accompanying burden of illness. A vaccine that protects against RSV is urgently required.

Key points: · Main indications were prematurity (63.3%); "miscellaneous" (17.8%); hemodynamically significant congenital heart disease (10.5%); bronchopulmonary dysplasia/chronic lung disease (8.4%).. · The proportion of children in the "miscellaneous" group, comprised of those with trisomy 21, airway anomalies, pulmonary disorders, cystic fibrosis, neurological impairments, immunocompromised, cardiac aged >2 years, multiple conditions, and a residual "unclassified" group, increased over time (4.4% in 2005-2006 to 22.5% in 2016-2017).. · Respiratory illness-related hospitalization occurred in 2,054 children (6.9%); 198 (9.6%) required intubation. Three hundred thirty-seven hospitalized children were RSV-positive (overall RSVH: 1.6%)..

Publication types

  • Observational Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiviral Agents / therapeutic use
  • Bronchopulmonary Dysplasia* / complications
  • Canada / epidemiology
  • Child
  • Cystic Fibrosis* / complications
  • Cystic Fibrosis* / drug therapy
  • Disease Progression
  • Down Syndrome* / complications
  • Female
  • Heart Defects, Congenital*
  • Hospitalization
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Palivizumab / therapeutic use
  • Prospective Studies
  • Respiratory Syncytial Virus Infections* / drug therapy
  • Respiratory Syncytial Virus Infections* / epidemiology
  • Respiratory Syncytial Virus Infections* / prevention & control
  • Respiratory Syncytial Virus, Human*

Substances

  • Palivizumab
  • Antiviral Agents

Grants and funding

Funding The Canadian Respiratory Syncytial Virus Evaluation Study of Palivizumab (CARESS) is funded by an investigator-initiated grant from AbbVie Corporation (A05-130).