Impact and cost-effectiveness of strategies to prevent respiratory syncytial virus (RSV) disease in Vietnam: A modelling study

Lien Anh Ha Do; Nguyen Thanh Nhan Le; Sarwat Mahmud; Kim Mulholland; Clint Pecenka; Andrew Clark

doi:10.1016/j.vaccine.2023.09.003

Impact and cost-effectiveness of strategies to prevent respiratory syncytial virus (RSV) disease in Vietnam: A modelling study

Vaccine. 2023 Sep 9;41(46):6782-6790. doi: 10.1016/j.vaccine.2023.09.003. Online ahead of print.

Authors

Lien Anh Ha Do¹, Nguyen Thanh Nhan Le², Sarwat Mahmud³, Kim Mulholland⁴, Clint Pecenka⁵, Andrew Clark³

Affiliations

¹ New Vaccines Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Pediatrics, The University of Melbourne, Melbourne, Australia. Electronic address: lienanhha.do@mcri.edu.au.
² Children's Hospital 1, Ho Chi Minh City, Viet Nam.
³ Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom.
⁴ New Vaccines Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Pediatrics, The University of Melbourne, Melbourne, Australia; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
⁵ PATH, Seattle, USA.

Abstract

Background: New prevention strategies for respiratory syncytial virus (RSV) are emerging, but it is unclear if they will be cost-effective in low- and middle-income countries. We evaluated the potential impact and cost-effectiveness of two strategies to prevent RSV disease in young children in Vietnam.

Methods: We used a static cohort model with a finely disaggregated age structure (weeks of age <5 years) to calculate the RSV disease burden in Vietnam, with and without a single dose of maternal vaccine (RSVpreF, Pfizer) or of monoclonal antibody (Nirsevimab, Sanofi, Astra Zeneca). Each strategy was compared to no pharmaceutical intervention, and to each other. We assumed both strategies would be administered year round over a ten-year period. The primary outcome measure was the cost per disability-adjusted life year (DALY) averted, from a societal perspective. We ran probabilistic and deterministic uncertainty analyses.

Results: With central input assumptions for RSVpreF vaccine ($25/dose, 69 % efficacy, 6 months protection) and Nirsevimab ($25/dose, 77 % efficacy, 5 months protection), both options had similar cost-effectiveness ($3442 versus $3367 per DALY averted) when compared separately to no pharmaceutical intervention. RSVpreF vaccine had a lower net cost than Nirsevimab (net discounted cost of $213 m versus $264 m) but prevented fewer RSV deaths (24 % versus 31 %). Our results were very sensitive to assumptions about the dose price, efficacy, and duration of protection. At $5/dose and a willingness-to-pay threshold of 0.5 times the national GDP per capita, both prevention strategies are cost-effective.

Conclusions: RSVpreF vaccine and Nirsevimab may be cost-effective in Vietnam if appropriately priced.

Keywords: Cost-effectiveness analysis; Low-income and middle-income countries (LMICs); Maternal vaccine; Monoclonal antibody; Respiratory syncytial virus (RSV).