Protecting infants against RSV disease: an impact and cost-effectiveness comparison of long-acting monoclonal antibodies and maternal vaccination

Abstract

Background: Two new products for preventing Respiratory Syncytial Virus (RSV) in young children have been licensed: a single-dose long-acting monoclonal antibody (la-mAB) and a maternal vaccine (MV). To facilitate the selection of new RSV intervention programmes for large-scale implementation, this study provides an assessment to compare the costs of potential programmes with the health benefits accrued.

Methods: Using an existing dynamic transmission model, we compared maternal vaccination to la-mAB therapy against RSV in England and Wales by calculating the impact and cost-effectiveness. We calibrated a statistical model to the efficacy trial data to accurately capture their immune waning and estimated the impact of seasonal and year-round programmes for la-mAB and MV programmes. Using these impact estimates, we identified the most cost-effective programme across pricing and delivery cost assumptions.

Findings: For infants under six months old in England and Wales, a year-round MV programme with 60% coverage would avert 32% (95% CrI 22-41%) of RSV hospital admissions and a year-round la-mAB programme with 90% coverage would avert 57% (95% CrI 41-69%). The MV programme has additional health benefits for pregnant women, which account for 20% of the population-level health burden averted. A seasonal la-mAB programme could be cost-effective for up to £84 for purchasing and administration (CCPA) and a seasonal MV could be cost-effective for up to £80 CCPA.

Interpretation: This modelling and cost-effectiveness analysis has shown that both the long-acting monoclonal antibodies and the maternal vaccine could substantially reduce the burden of RSV disease in the infant population. Our analysis has informed JCVI's recommendations for an RSV immunisation programme to protect newborns and infants.

Funding: National Institute for Health Research.

Keywords: Cost-effectiveness; Mathematical modelling; RSV; Vaccination.

Fig. 1

Estimating waning protection from maternal vaccination and monoclonal antibodies. A) Cartoon of the Bayesian fitting procedure for determining the time-varying protection from infection and disease from Kaplan Meier plots. B) The fitted time-varying probability of protection (mean: black lines, 95% CrI: grey area) with the quoted efficacy from clinical trial studies (red lines).

Fig. 2

Impact of the programmes across age groups. Black lines show the median proportional reduction in cases of six health outcomes for the maternal and la-mAB programmes. The shaded areas show the 95% CrI of the posterior distribution.

Fig. 3

A) The per dose efficiency for each programme considered. The uncertainty is shown at the 50% CrI (thick black line) and 95% CrI (thin black line) B) The distribution of the discounted QALY gain over ten years for each of the five intervention programmes C) The distribution of the healthcare cost saving over ten years for each of the five intervention programmes (not including the price of implementing the programme).

Fig. 4

A) Optimal intervention programmes according to the cost-effectiveness of the programme for a combined cost of purchasing and administration (CCPA) for maternal vaccines (x-axis) and monoclonal antibodies (y-axis) assuming a £20,000/QALY threshold. The optimal programme is the coloured tile corresponding to a CCPA for MV and la-mAB. (B) The EVPI for a given CCPA of maternal vaccines (x-axis) and monoclonal antibodies (y-axis). Note: the year-round seasonal programme is dominated by the seasonal with catch-up programme in the CEA, and therefore not shown in this plot.

Fig. 5

Stacked bar charts showing the optimal programme from the Monte Carlo samples assuming the same CCPA for MV and la-mAB but different coverages.