AstraZeneca announces new data showing US preterm infants at significantly greater risk of RSV hospitalizations following 2014 guidance change

Data demonstrate a greater increase in RSV hospitalization risk during the 2015-2016 RSV season compared to recently published data from the prior season

AstraZeneca today announced new results of a study that investigated respiratory syncytial virus (RSV) hospitalization risk and costs during the 2014-2016 RSV seasons compared to the 2012-2014 RSV seasons. Results of the study were presented as a poster on Wednesday, October 18 at the Academy of Managed Care Pharmacy (AMCP) Nexus meeting in Dallas, TX. This study is the first national analysis of serious RSV disease in US preterm infants from the two seasons following the 2014 American Academy of Pediatrics (AAP) guidance that recommended against the use of RSV immunoprophylaxis in preterm infants born at 29-34 weeks gestational age (wGA). The 2014 guidance asserted that 29-34 wGA infants were not at a significantly increased risk of RSV hospitalization relative to full-term (FT) infants.

The study demonstrated that RSV immunoprophylaxis use declined dramatically in preterm infants born at 29-34 wGA in 2014-2016 relative to 2012-2014, consistent with recommendations in the 2014 guidance. Associated with this decline, RSV hospitalization risks increased among infants 29-34 wGA who were <6 months of age for both Commercial-insured and Medicaid-insured infants. Preterm infants 29-34 wGA who were <6 months of age were approximately 2.5 to 5 times more likely to be hospitalized than FT infants in 2014-2015, which increased to approximately 3.5 to 5.5 times more likely in 2015-2016. These risks were higher than those observed in seasons prior to the guidance change.

This study confirms and extends the results of a recently published study that similarly demonstrated a significant national increase in RSV hospitalizations among infants 29-34 wGA who were <3 months of age during the 2014-2015 RSV season compared to the previous four seasons.

Greg Keenan, Vice President, US Medical Affairs, AstraZeneca said: “The results from this study emphasize that preterm infants are at substantially elevated risk of RSV hospitalization compared to full-term infants. As a science-led organization, AstraZeneca remains committed to partnering with the academic community to conduct research that characterizes and ultimately reduces the burden of disease for this vulnerable population of patients.”

The study examined national US Commercial and Medicaid insurance claims databases containing data from more than 1.5 million claims of infants <1 year of age. In addition to the increased RSV hospitalization risks among preterm infants, the study found that RSV hospitalization costs were also higher. The average RSV hospitalization cost during the 2014-2016 RSV seasons for Commercial infants <3 months of age at first RSV hospitalization was $17,416 for FT infants and $39,174 for infants 29–34 wGA. The average cost for Medicaid infants <3 months of age at first RSV hospitalization was $9,824 for FT infants and $22,316 for infants 29-34 wGA. RSV hospitalizations were identified using ICD-9-CM diagnosis codes on inpatient claims; confirmatory laboratory results were not available for this study, as insurance claims databases do not provide these results.

Utilization of inpatient RSV immunoprophylaxis among infants <3 months of age discharged from their birth hospitalization during the RSV season is not recorded in claims databases, and this could impact rates of RSV hospitalization in this subgroup. RSV immunoprophylaxis use prior to discharge would be expected to reduce RSV hospitalization rates in infants <3 months of age.

Dr. Mitchell Goldstein, from Loma Linda University Children’s Hospital, Loma Linda, CA and the lead author of the study, said: “RSV is the leading cause of hospitalization for infants in their first year of life in the United States and can be especially severe for preterm infants during the first months of life. These data build on previous studies and should prompt additional discussion of the importance of RSV prevention efforts among these high-risk infants. This is an important topic among advocates for preterm infant health and the health care community.”


About the study
Between July 1, 2012 and June 30, 2016, RSV hospitalization risks were evaluated during the RSV season of each year. Rates were calculated per 100 infant-seasons. RSV hospitalization costs for the 2014–2016 seasons were averaged separately for FT and preterm infants by age at first RSV hospitalization.  

Children with chronic lung disease of prematurity or hemodynamically significant congenital heart disease were not studied. These populations have risks of severe RSV disease above those observed with otherwise healthy preterm infants and continue to be recommended for RSV immunoprophylaxis.

Results of the study were presented as a poster on Wednesday, October 18 at the Academy of Managed Care Pharmacy (AMCP) Nexus meeting in Dallas, TX.

About RSV
RSV is a contagious, seasonal respiratory virus that nearly 100% of children will contract, at varying levels of severity, by the age of two and most will recover from within one to two weeks. In certain high-risk babies, however, RSV can lead to a serious lung infection and hospitalization. Preterm infants are at increased risk of developing severe RSV disease because their lung volume is significantly less than that of full-term infants, and their airways are smaller and narrower than those of a baby born at term.

About AstraZeneca
AstraZeneca is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialization of prescription medicines, primarily for the treatment of diseases in three main therapy areas – Oncology, Cardiovascular & Metabolic Diseases and Respiratory. The Company also is selectively active in the areas of autoimmunity, neuroscience and infection. AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide. For more information, please visit and follow us on Twitter @AstraZenecaUS.


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