Study type

Study topic

Human medicinal product

Study type

Non-interventional study

Scope of the study

Effectiveness study (incl. comparative)

Data collection methods

Secondary use of data
Non-interventional study

Non-interventional study design

Case-control
Study drug and medical condition

Name of medicine

ABRYSVO

Anatomical Therapeutic Chemical (ATC) code

(J07BX05) respiratory syncytial virus vaccines
respiratory syncytial virus vaccines

Medical condition to be studied

Respiratory syncytial virus immunisation
Population studied

Short description of the study population

The study population will include infants who were hospitalized with ARI, have documented RSV test results and born to an individual eligible for ABRYSVO vaccination in pregnancy based on the timing of birth relative to the local seasonal ABRYSVO vaccination program.

Age groups

Preterm newborn infants (0 – 27 days)
Term newborn infants (0 – 27 days)
Infants and toddlers (28 days – 23 months)

Special population of interest

Pregnant women
Study design details

Study design

This study uses UPMC electronic medical records to evaluate the real-world vaccine effectiveness of maternal ABRYSVO vaccination against RSV in infants and describes medically-attended visits for infants exposed to ABRYSVO and Beyfortus, with no active enrollment or direct participant contact.

Main study objective

Estimate ABRYSVO VE against RSV positive acute respiratory illness (ARI) hospitalization among infants from birth through 3 months (0 through 90 days of age).

Setting

This health network-based retrospective study will be conducted using data from University of Pittsburgh Medical Center (UPMC), a semi-closed health network in Western Pennsylvania.
Two UPMC hospitals will be utilized to identify the source population in this study – UPMC Magee-Women’s Hospital, which serves Pittsburgh, Pennsylvania and the surrounding area and has over 9,000 deliveries per year, and UPMC Hamot Hospital, which serves Erie, Pennsylvania and has over 3,000 deliveries per year. The integrated electronic health record at these hospitals allows for >95% of mothers and their infants to be linked within the EHR allowing for accurate characterization of maternal immunization. Furthermore, both hospitals participate in the Magee Obstetric Maternal & Infant (MOMI) Database, which collects over 300 maternal and infant variables from pregnancy, delivery, and postpartum for every pregnancy, allowing for standardized data collection for >95% of deliveries occurring in these hospitals.

The University of Pittsburgh and UPMC’s bioinformatics group (R3) can routinely obtain structured data elements from the electronic health record including maternal and infant immunization records, laboratory results, medications, diagnosis codes, demographic and birth characteristics. Additional details of specific medical encounters, including details on reported clinical symptoms, vital signs, and physical exam findings, can be obtained using unstructured data abstraction with trained data abstractors, who enter data directly into electronic data collection tool. This detailed abstraction will allow for accurate characterization of viral infection that includes LRTD.

Outcomes

The outcome for the primary objective is RSV-positive ARI hospitalization confirmed by ≥1 acute respiratory illness symptom, laboratory testing, and hospitalization occurring 0 to ≤ 90 days of life during RSV season based on local epidemiology.

Outcomes for the secondary objective include:
- RSV-positive ARI hospitalization confirmed by ≥1 acute respiratory illness symptom, laboratory testing, and hospitalization occurring 0 to ≤ 180 days of life during RSV season based on local epidemiology.
- RSV -positive ARI hospitalization confirmed by ≥ 1 acute respiratory illness symptom, laboratory testing, and hospitalization occurring 90 to ≤180 days of life during the RSV season based on local epidemiology.
- RSV-positive ARI hospitalization with study-defined LRTD occurring 0 to ≤ 90 days of life during RSV season based on local epidemiology.
- RSV-positive hospitalization with study-defined LRTD occurring 0 to ≤180 days of life during RSV season based on local epidemiology.
- RSV-positive ARI hospitalization with study-defined LRTD occurring 90 to ≤ 180 days of life during RSV season based on local epidemiology.
- Number, age and characteristics of infants whose birth parent received ABRYSVO during pregnancy who present for a medical visit (outpatient, urgent care, emergency room, hospital) and have laboratory confirmed RSV between 0 to ≤ 90 days of life.
- Number, age and characteristics of infants who received Beyfortus between 0 to <7 days of life who present for a medical visit (outpatient, urgent care, emergency room, hospital) and have laboratory confirmed RSV between 1 to ≤ 90 days post-Beyfortus exposure.

The exploratory outcome is RSV-positive ARI hospitalization confirmed by ≥1 acute respiratory illness symptom, laboratory testing, and hospitalization occurring 0 to ≤30 days of life during RSV season based on local epidemiology.

Data analysis plan

For the TND study, baseline characteristics of the study population will be described by case/control status and by exposure status. A logistic regression model will be used to compute an odds ratio (OR), comparing the odds of maternal ABRYSVO vaccination during pregnancy between test-positive cases and test-negative controls. From the OR, the VE will be calculated as (1−OR) x 100%. A multivariable logistic regression model will be used to compute an adjusted OR (aOR) from which we will derive final VE estimates, adjusted for potential confounding, according to the formula: VE = (1−aOR) x 100%. The same approach will be utilized for secondary and exploratory VE objectives.

For descriptive objectives, age at RSV+ medically attended visit as well as other descriptive characteristics such as demographics, co-morbid medical conditions, and location of medical visit will be described for infants exposed to ABRYSVO and Beyfortus.