Study to Evaluate the Incidence of Hospitalizations and Respiratory Tract Infections in Premature Infants

The goals of this study are:

• To estimate the incidence of hospitalization attributable to RSV within 150 days from enrollment in premature infants who are:

• 32-35 weeks GA
• less than 6 months of age at the start of the RSV season
• not receiving palivizumab prophylaxis and not recommended to receive palivizumab according to the AAP guidelines
• To estimate the incidence rate of hospitalization attributable to RSV in the other relevant study populations and time periods (e.g., Cohort 2, Cohorts 1 and 2 combined, and subgroups based on chronological age at the start of the RSV season, GA, etc. within 150 days from enrollment and other time periods based on RSV activity, etc.)
• To estimate the incidence of RSV-associated MALRI in the study populations
• To characterize the incidence and type of clinical interventions for MALRI in the study populations

Inclusion criteria

• Parent/legal guardian able to understand and provide written informed consent
• Male or female infants born at 32-35 weeks GA. GA will be determined according to available medical records.
• Clinically stable, in the opinion of the investigator
• Ability and willingness of the subject's parent/legal guardian to complete all protocol mandated follow-up telephone calls, visits and procedures
• Not more than one of the following American Academy of Pediatrics (AAP)-defined risk factors:

• Childcare attendance
• School-aged siblings in the home
• Exposure to environmental air pollutants (not including passive exposure to tobacco smoke)
• Congenital abnormalities of the airways
• Severe neuromuscular disease, as determined by the investigator
• Subject must meet the criteria listed below for either Cohort 1 or Cohort 2:

Cohort 1

• Date of enrollment between 01/Oct and 15/Dec
• Chronological age of < 6 months (i.e., has not yet reached 6-month birthday) at the traditional start of the local RSV season (as used to determine eligibility for RSV prophylaxis)

Cohort 2

• Date of enrollment between 16/Dec and 15/Feb
• Born during the current RSV season and discharged from the hospital nursery after 01/Dec

Exclusion criteria

• Previous (within 90 days of enrollment) or concurrent treatment with palivizumab or RSV-IGIV or IVIG
• Hospitalization at the time of enrollment (unless discharge is anticipated within 10 days)
• Two or more AAP-defined risk factors as listed under Inclusion Criteria
• Participation in trials of investigational RSV prophylaxis or therapeutic agents
• Confirmed prior or current RSV infection (a child with current signs/symptoms of respiratory infection must have negative RSV testing)
• Diagnosis of chronic lung disease (CLD) of prematurity (formerly referred to as bronchopulmonary dysplasia [BPD])
• Diagnosis of hemodynamically significant congenital heart disease (CHD), defined as requiring medication or supplemental oxygen for their CHD
• Known immunodeficiency
• Life expectancy of < 6 months