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

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

Respiratory Syncytial Virus: Knowledge, Attitudes and Beliefs of General Practitioners from North-Eastern Italy (2021)

“…On the other hand, RSV vaccines are commercially unavailable [ 1 , 3 , 9 , 12 , 13 ], and preventive interventions are limited to monoclonal antibodies (mAb) [ 14 , 15 , 16 ]. Despite their efficacy in avoiding hospitalizations and long-term sequelae, their use is forcibly limited to some high-risk groups (i.e., prematurely-born infants under 6 months of age, and children with certain comorbidities under 2 years of age during the RSV season) [ 9 , 17 , 18 , 19 , 20 , 21 ].…”

Respiratory Syncytial Virus Prevention through Monoclonal Antibodies: A Cross-Sectional Study on Knowledge, Attitudes, and Practices of Italian Pediatricians

“…In this cross-sectional study on a sample of Italian Pediatricians, the participants exhibited a largely favorable attitude towards the implementation of mAb as an instrument to prevent RSV complications. Interestingly, mAb were also extensively acknowledged as useful for avoiding natural infections, possibly overstating their actual efficacy [ 24 , 29 , 37 , 38 , 39 , 71 ]. However, despite this largely positive attitude, the sampled professionals reported a relatively infrequent use of mAb in their clinical practice: in fact, only 14.4% of the total sample, but also no more than 34.4% of the subgroup of participants with any previous expertise in the managing of RSV, had previously delivered mAb as a preventative item.…”

“…Collectively, such features could explain the favorable attitude towards an intervention that is perceived as both accessible and effective, as well as the substantial lack of familiarity with mAb in the clinical practice. Indeed, official recommendations for palivizumab are quite restrictive [ 10 , 16 , 27 , 29 , 30 , 31 ], prioritizing or even limiting the use of this drug on very selective groups of infants [ 34 ], and only after the conclusion of this survey’s extended half-life have mAb, such as nirsevimab, been available in the EU [ 35 , 36 , 38 ]. As nirsevimab’s easier and potentially more affordable handling could radically increase the share of targeted infants, it is quite reasonable that also the familiarity of clinical practitioners could increase in the next years [ 4 , 11 , 35 , 36 , 37 , 38 , 82 ].…”

“…Despite its proven efficacy, this is a relatively expensive medication, as the cost for a 100-mg vial usually ranges from 904$ to 1866$ [ 4 , 5 , 24 , 25 , 26 , 28 ]. Moreover, guideline indications have become increasingly restrictive, and a palivizumab license is currently limited to some high-risk groups [ 10 , 16 , 27 , 29 , 30 , 31 ], including: (a) infants born at ≤ 35 weeks of Gestational Age (wGA); (b) children < 2 years of age affected by chronic lung disease of prematurity (CLD); and (c) children < 2 years of age affected by hemodynamically significant congenital heart disease (CHD) [ 32 , 33 , 34 ]. Nevertheless, not only have recommendations changed over the years, but stronger limitations have been issued depending on countries’ public health policies [ 25 , 26 , 28 ].…”

Cost-effectiveness of RSVpreF vaccine and nirsevimab for the prevention of respiratory syncytial virus disease in Canadian infants

“…A single dose of palivizumab was assumed to be 70% and 80% effective in preventing RSV MA-LRTI and hospitalization in infants at high-risk, respectively (23). It was also assumed that a single dose of palivizumab would provide one-month of protection, with infants receiving five doses during their first RSV season (24).…”