Cost-effectiveness of rotavirus vaccination in the Philippines: A modeling study

Introduction: Rotavirus gastroenteritis (RVGE) remains a leading cause of hospitalization and death in children under five years of age in the Philippines. Rotavirus (RV) vaccination was introduced into the national immunization program (NIP) in 2012 but has since been limited to one region due to cost con-siderations and conflicting local cost-effectiveness estimates. Updated estimates of the cost-effectiveness of RV vaccination are required to inform prioritization of national immunization activities. Methods: We calculated the potential costs and benefits of rotavirus vaccination over a 10-year-period (2021-2031) from a government and societal perspective, comparing four alternative rotavirus vaccines: Rotavac, Rotasiil, Rotarix and Rotateq. For each vaccine, a proportionate outcomes model was used to cal-culate the expected number of disease events, DALYs, vaccination program costs, and healthcare costs, with and without vaccination. The primary outcome measure was the cost per DALY averted. Assuming each product would generate similar benefits, the dominant (lowest cost) product was identi-fied. We then calculated the cost-effectiveness (US$ per Disability Adjusted Life Year [DALY] averted) of the least costly product and compared it to willingness-to-pay thresholds of 0.5 and 1 times the national GDP per capita ($3,485), and ran deterministic and probabilistic sensitivity analyses. Results: Introducing any of the four rotavirus vaccines would avert around 40% of RVGE visits, hospital-izations, and deaths over the period 2021-2031. Over the same ten-year period, the incremental cost of vaccination from a government perspective was estimated to be around $104, $105, $220, and $277 mil-lion for Rotavac, Rotasiil, Rotarix and Rotateq, respectively. The equivalent cost from a societal perspec-tive was $58, $60, $178 and $231 million. The cost-effectiveness of the least costly product (Rotavac) was $1,148 ($830-$1682) from a government perspective and $646 ($233-1277) from a societal perspective. All other products offered similar benefits but at a higher cost. There is a >99% probability that Rotavac would be cost-effective at a willingness-to-pay threshold set at 0.5 times the national GDP per capita. Conclusion: Both Rotavac and Rotasiil are likely to be cost-effective options in the Philippines, but it is not possible to say definitively which product should be preferred. Rotarix and Rotateq are expected to offer similar benefits at more cost, so would need to be priced far more competitively to be considered for introduction. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).