Pfizer Maternal RSV Vaccine Could Reduce Infant Clinical Events by Tens of Thousands, Costs by $800 Million

This article is part of our IDWeek 2023 coverage. You can find all of our news here.

An analysis of the public health impact of maternal vaccination with the Pfizer bivalent stabilized prefusion F subunit vaccine (RSVpreF) to prevent RSV-related lower respiratory tract infection (LRTI) among US infants revealed a potential reduction of tens of thousands of outpatient and emergency department (ED) visits and hospitalizations as well as projected savings to the healthcare system in direct and indirect costs of more than $800 million.

The findings come from a study highlighted during oral abstract presentations at IDWeek 2023 in Boston, MA, running from October 11 -15, 2023.

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract illness (LRTI) among young children and can lead to severe disease including bronchiolitis and pneumonia. In April, the US Food and Drug Administration granted approval to Pfizer for the company’s bivalent stabilized RSVpreF vaccine for pregnant people to protect their infants against RSV-LRTI, the first of its kind.

During clinical trials, the company evaluated the potential public health impact of the maternal vaccine in a single year which it measured as the reduction in clinical outcomes and economic costs.

Using a cohort model, investigators depicted clinical outcomes and economic costs of RSV-LRTI from birth to age 1 year, lifetime consequences of premature death, and impact of maternal vaccination with RSVpreF among infants.

Projections of clinical outcomes (by month) were based on infant age, gestational age in weeks (wGA) at birth, RSV disease and fatality rates, and mother’s vaccination status; cases included medically attended RSV-LRTI and RSV-LRTI deaths.

Efficacy of maternal vaccination with RSVpreF was derived from interim trial analyses, according to the study abstract. The investigators’ analysis assumed variation by clinical presentation (hospital vs ambulatory), timing of vaccine administration relative to birth, and wGA at birth.

The team generated economic costs based on cases and corresponding unit costs. The public health impact of RSVpreF was evaluated assuming year-round use and 100% uptake.

FINDINGS

The analysis projected that without use of the maternal RSVPreF vaccine there would be 48 246 hospitalizations, 144 495 ED encounters, and 399 313 outpatient clinic visits annually presuming a US birth cohort of 3.7M infants aged younger than 12 months. Projections after presumptive maternal vaccination with RSVpreF resulted in a reduction of 24 520 hospitalizations, 45 957 ED encounters, and 128 745 OC visits. This reduction in clinical events was linked with a corresponding decrease in direct medical costs equal to $691.8 million and indirect (non-medical) costs equal to $110.0 million.

 The investigators state that their results from the evaluation indicate that maternal vaccination with RSVpreF would “substantially reduce” the clinical and economic burden of RSV-LRTI in infants. “These results may be conservative,” the added, “as we did not include potential for reductions in outcomes such as maternal RSV disease, household transmission, and long-term sequelae such as asthma.”

Source: Hanau A, Shea KM, Weycker D, et al. Potential public health impact of bivalent respiratory syncytial virus prefusion (RSVpreF) maternal vaccine for prevention of RSV among US infants. Abstract presented at IDWeek 2023; October 11-15, 2023; Boston, MA.