(688) Hybrid versus natural immunity to protect against neonatal hospitalization: A Cost-Effectiveness Analysis

Friday, January 31, 2025

10:30 AM – 12:30 PM

Submitting Author and Presenting Author(s)

Amelia H. Gagliuso, BA (she/her/hers)

Medical Student
Oregon Health & Sciences University
Portland, OR, United States

Coauthor(s)

LB

Lily Ben Avi, BA

Oregon Health & Science University
Portland, Oregon, United States
Sarah K. Dzubay, BS (she/her/hers)

MD-MPH student
Oregon Health & Science University
Portland, Oregon, United States
NM

Nicole E. Marshall, MD

Associate Professor
Oregon Health & Science University
Portland, Oregon, United States
Aaron B. Caughey, MD, PhD

Professor and Chair
Oregon Health & Science University
Portland, Oregon, United States

Objective: Neonates are ineligible for COVID-19 vaccination and are at increased risk for complications from COVID-19 infections compared with vaccine-eligible populations. Passive immunity from maternal anti-SARS-COV-2 immunoglobulins crossing the placenta and in human milk demonstrates that vaccine-mediated immunity compared to natural immunity is clinically beneficial for both maternal and infant outcomes as shown with TdaP and influenza. The purpose of this analysis was to determine the cost-effectiveness of maternal hybrid immunity in protection against neonatal outcomes in the United States.

Study Design: A TreeAge model was constructed to compare outcomes for a theoretical cohort that were vaccinated with one dose and had a previous infection (Hybrid immunity) with those who received no vaccine and had a previous infection (Natural immunity). Our cohort contained 3,664,292 individuals, the estimated number of annual live births in the United States. Model outcomes included cases of neonatal deaths, neurodevelopmental disabilities, and neonatal hospitalization. Probabilities, utilities, and costs were derived from literature. QALYs were discounted at a rate of 3%.

Results: Hybrid immunity in our theoretical cohort was associated with a decrease in 462 neonatal deaths, 482 cases of neurodevelopmental delay, and 132 cases of neonatal hospitalization (Table 1). Hybrid immunity was the dominant strategy as it saved $2,981,154,191 and led to 32,619 additional QALYs (Table 1). Univariate sensitivity analysis demonstrated that the COVID-19 vaccine is cost-saving until the cost of the vaccine exceeds $500, which is far above the current price (Figure 1).

Conclusion: This study demonstrates that vaccination even among those with a previous infection improves outcomes and is cost saving in pregnant persons. Ensuring that all pregnant people are aware of the positive impact on their neonates from obtaining the COVID vaccine during pregnancy is important to achieve these potential benefits.