Nirsevimab, maternal vaccine reduce medical spending for RSV

BySara Kellner

Fact checked byCarol L. DiBerardino, MLA, ELS

Key takeaways:

Nirsevimab could prevent an estimated 14,341 RSV-associated hospitalizations and 14 deaths per year.
Maternal RSV vaccination could prevent an estimated 7,571 hospitalizations and eight deaths per year.

Nirsevimab and the maternal vaccine for respiratory syncytial virus can reduce health care costs and productivity losses associated with RSV but lead to higher overall spending, according to analyses published in Pediatrics.

“Respiratory syncytial virus is an important cause of disease burden in infants in the United States, costing $472 million per year,” David W. Hutton, PhD, professor of health management and policy and global public health at the University of Michigan School of Public Health, and colleagues wrote.

Infant vaccine Stock — Nirsevimab and the maternal respiratory syncytial virus vaccine reduced health care costs, according to two cost-effectiveness analyses. *Image: Adobe Stock.*

According to the CDC and the American College of Obstetricians and Gynecologists, the maternal RSV vaccine can be administered to pregnant women between 32 and 36 weeks’ gestational age to protect infants during their first 6 months of life. The CDC and AAP recommend nirsevimab, a monoclonal antibody, for infants up to age 8 months who are entering their first RSV season, and children up to age 19 months entering their second season who have a high risk for severe RSV disease. Babies born less than 14 days after their mother gets the maternal vaccine are also recommended to receive nirsevimab, according to the CDC.

Both immunizations were approved by the FDA in 2023.

The cost-effectiveness analyses that Hutton and colleagues wrote was used by the CDC’s Advisory Committee on Immunization Practices in developing recommendations for each immunization.

Hutton and colleagues simulated the burden of RSV infection, disease and deaths in the U.S. with and without the use of nirsevimab and the maternal RSV vaccine. They used 2016 to 2020 data from the CDC and 2015 to 2019 data the National Respiratory and Enteric Virus Surveillance System to estimate RSV prevalence without immunizations. Then, the authors used the simulations to estimate the societal costs of RSV infection and how these immunizations can offset those costs over a lifetime. They reported monetary data in 2022 dollars with 3% inflation.

In addition to monetary outcomes, Hutton and colleagues calculated the quality-adjusted life years (QALYs) that children and caregivers would lose with RSV, which they factored into the cost-effectiveness of each intervention.

Nirsevimab cost-effectiveness

The researchers estimated that if half of infants born during RSV season received nirsevimab, there would be 107,253 fewer outpatient visits, 38,204 fewer ED visits, 14,341 fewer hospitalizations and 14 fewer deaths compared with a year without nirsevimab.

They also found that every 128 infants immunized with nirsevimab would prevent one hospitalization.

Estimated total costs were higher with nirsevimab than without ($2.085 billion vs. $1.651 billion), Hutton and colleagues found. The biggest difference was the cost of RSV interventions, like palivizumab and nirsevimab ($969 million) vs. palivizumab alone ($225 million). However, spending on RSV medical care was $195 million lower and productivity costs were $115 million lower with nirsevimab than without ($560 million vs. $755 million and $556 million vs. $671 million, respectively).

The nirsevimab model resulted in 2,827 more QALYs for children and their caregivers. The societal cost per QALY gained was $153,517, the researchers found. In their second RSV season, the cost of receiving nirsevimab was more than $1.6 million per QALY gained for a child with an average risk for hospitalization, whereas the cost of nirsevimab was $308,468 per QALY gained for a child with a 10-times higher risk for hospitalization.

The price of nirsevimab doses, medical care and losses due to RSV disease had a significant impact on the cost per QALY gained, Hutton and colleagues noted, and in scenarios where nirsevimab doses were cheaper or hospitalization costs were higher than average, the immunization could save money overall.

Because nirsevimab is likely to decrease RSV-related health care costs for infants and their families, it “could potentially be a cost-effective way to reduce RSV burden in infants in their first RSV season,” the authors wrote. “Administering nirsevimab to all young children in their second season is unlikely to be cost-effective, but it may be cost-effective for certain young children at a significantly higher risk of severe outcomes from RSV.”

Maternal vaccine cost-effectiveness

The researchers ran a similar simulation comparing RSV prevalence and costs with and without the maternal RSV vaccine for half of pregnant women during a given respiratory season. The analysis did not include nirsevimab.

In their model, the maternal vaccine prevented an estimated 45,693 outpatient visits, 15,866 ED visits, 7,571 hospitalizations and eight RSV deaths. One hospitalization would be prevented for every 234 pregnant women who get vaccinated, Hutton and colleagues found.

Like the nirsevimab model, total costs were higher with the maternal vaccine than without ($2.164 billion vs. $1.651 billion), mostly due to greater spending on RSV interventions ($891 million with the maternal vaccine vs. $225 million without). Medical costs and productivity losses were lower with the vaccine than without ($656 million vs. $755 million and $617 million vs $671 million, respectively).

Hutton and colleagues estimated the vaccine would lead to 1,294 additional QALYs for infants and caregivers, with a societal cost of $396,280 per QALY gained and $67,735 per RSV hospitalization avoided.

The researchers calculated the cost-effectiveness of the vaccine for a variety of scenarios. By adding a 1% probability of preterm birth compared with 0%, the cost per QALY gained increased fourfold, Hutton and colleagues found.

They also learned that the cost-effectiveness of the vaccine changed based on which month it was administered. When the vaccine was administered between September and January, the cost per QALY gained was $163,513. The most cost-effective month was November at $107,544 per QALY gained.

The authors also ran a simulation with both nirsevimab and the maternal vaccine as options for RSV prevention, which found the cost of the maternal vaccine increased dramatically “because RSVpreF offers marginal additional protection beyond what might be expected from nirsevimab alone.” In that scenario, the most cost-effective month to administer the maternal vaccine was April because it would offer protection at the beginning of the next RSV season, however, the cost per QALY gained was $2.4 million.

“Caution is urged in directly comparing the results of these models because the model inputs are based on efficacy trials with different definitions of outcomes, and the duration of the protection of both products remains unknown,” Hutton and colleagues wrote.