Respiratory syncytial virus immunoprophylaxis in high-risk infants and development of childhood asthma

Abstract

Background Respiratory syncytial virus (RSV) lower respiratory tract infection is implicated in asthma development. RSV immunoprophylaxis during infancy is efficacious in preventing RSV hospitalizations and has been associated with decreased wheezing in the first years of life. Objective We investigated whether greater adherence to immunoprophylaxis in infants at high-risk for severe RSV would be associated with decreased childhood asthma. Methods We conducted a retrospective cohort investigation including children born 1996-2003, enrolled in Kaiser Permanente Northern California or Tennessee Medicaid, and eligible to receive RSV immunoprophylaxis. Asthma was defined at 4.5-6 years using asthma-specific healthcare visits and medication fills. We classified children into immunoprophylaxis eligibility groups and calculated adherence (% receipt of recommended doses). We employed a set of statistical strategies (multivariable logistic regression, propensity score (PS)-adjusted and-matched analyses) to overcome confounding by medical complexity, as infants with higher adherence (≥70%) have higher prevalence of chronic lung disease, lower birth weight, and longer nursery stays. Results Using multivariable logistic regression and PS-adjusted models in the combined group, higher adherence to RSV immunoprophylaxis was not associated with decreased asthma. However in PS-matched analysis, treated children with ≥70% adherence had decreased odds of asthma compared to those with ≤20% adherence (odds ratio 0.62: 95% CI 0.50, 0.78). Conclusions This investigation of RSV immunoprophylaxis in high-risk children primarily found non-significant associations on prevention of asthma in specific preterm groups. Findings highlight need for larger studies, prospective cohorts, and provide estimates of potential preventive effect sizes in high-risk children.

Role of viral infections in the development and exacerbation of asthma in children

“…59 Two studies of RSV immunoprophylaxis with palivizumab in preterm or high-risk infants demonstrated that prevention of more severe RSV-induced illness decreased recurrent wheezing but not atopic asthma. 60,61…”

Asthma and viral infections

“…Another RSV antibody, motavizumab, administered to a high-risk group in the first year of life reduced the risk of hospital admissions for wheezing by 87% but did not lead to a reduction in medically treated wheezing between 1 and 3 years of age. 49 Taken together, these studies indicate that monoclonal antibody therapy directed against RSV in preterm infants can reduce bronchiolitis and recurrent wheezing. Whether similar results would be seen in full-term infants remains to be demonstrated.…”

Respiratory syncytial virus prophylaxis for prevention of recurrent childhood wheeze and asthma: a systematic review

“…Two studies (Carroll et al and Simoes et al) [38] [41] were graded as being of very low quality with serious risk of bias. Carrol et al was deemed to show considerable risk of bias given infants most at risk of both RSV and development of recurrent wheeze, were more likely to have increased uptake and compliance with monoclonal antibody prophylaxis, potentially skewing results.…”