The azithromycin to prevent wheezing following severe RSV bronchiolitis-II clinical trial: Rationale, study design, methods, and characteristics of study population

Mythili Srinivasan*, Leonard B. Bacharier, Charles W. Goss, Yanjiao Zhou, Jonathan Boomer, Sarah Bram, Dana Burgdorf, Carey Ann Burnham, Timothy Casper, Mario Castro, Andrea Coverstone, Matthew Haslam, Watcharoot Kanchongkittiphon, Cadence Kuklinski, Qinghua Lian, Kenneth Schechtman, Gregory A. Storch, Kelly True, Meghan A. Wallace, Huiqing Yin-DeClueElizabeth Ahrens, Jinli Wang, Avraham Beigelman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Severe respiratory syncytial virus (RSV) bronchiolitis in early life is a significant risk factor for future recurrent wheeze (RW) and asthma. The goal of the Azithromycin to Prevent Wheezing following severe RSV bronchiolitis II (APW-RSV II) clinical trial is to evaluate if azithromycin treatment in infants hospitalized with RSV bronchiolitis reduces the occurrence of RW during the preschool years. The APW-RSV II clinical trial is a double-blind, placebo-controlled, parallel-group, randomized trial, including otherwise healthy participants, ages 30 days-18 months, who are hospitalized due to RSV bronchiolitis. The study includes an active randomized treatment phase with azithromycin or placebo for 2 weeks, and an observational phase of 18–48 months. Two hundred participants were enrolled during three consecutive RSV seasons beginning in the fall of 2016 and were randomized to receive oral azithromycin 10 mg/kg/day for 7 days followed by 5 mg/kg/day for an additional 7 days, or matched placebo. The study hypothesis is that in infants hospitalized with RSV bronchiolitis, the addition of azithromycin therapy to routine bronchiolitis care would reduce the likelihood of developing post-RSV recurrent wheeze (≥3 episodes). The primary clinical outcome is the occurrence of a third episode of wheezing, which is evaluated every other month by phone questionnaires and during yearly in-person visits. A secondary objective of the APW-RSV II clinical trial is to examine how azithromycin therapy changes the upper airway microbiome composition, and to determine if these changes are related to the occurrence of post-RSV RW. Microbiome composition is characterized in nasal wash samples obtained before and after the study treatments. This clinical trial may identify the first effective intervention applied during severe RSV bronchiolitis to reduce the risk of post-RSV RW and ultimately asthma.

Original languageEnglish
Article number100798
JournalContemporary Clinical Trials Communications
StatePublished - Jun 2021
Externally publishedYes


FundersFunder number
National Heart, Lung, and Blood InstituteR01HL130876, NCT02911935


    • Asthma
    • Azithromycin
    • Microbiome
    • Recurrent wheezing
    • Respiratory syncytial virus (RSV) bronchiolitis


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