Cost-effectiveness of norovirus vaccination in children in Peru

Abstract

Background: With candidate norovirus (NV) vaccines in a rapid phase of development, assessment of the potential economic value of vaccine implementation will be necessary to aid health officials in vaccine implementation decisions. To date, no evaluations have been performed to evaluate the benefit of adopting NV vaccines for use in the childhood immunization programs of low- and middle-income countries.

Methods: We used a Markov decision model to evaluate the cost-effectiveness of adding a two-dose NV vaccine to Peru's routine childhood immunization schedule using two recent estimates of NV incidence, one for a peri-urban region and one for a jungle region of the country.

Results: Using the peri-urban NV incidence estimate, the annual cost of vaccination would be $13.0 million, offset by $2.6 million in treatment savings. Overall, this would result in 473 total DALYs averted; 526,245 diarrhea cases averted;153,735 outpatient visits averted; and 414 hospitalizations averted between birth and the fifth year of life. The incremental cost-effectiveness ratio would be $21,415 per DALY averted; $19.86 per diarrhea case; $68.23 per outpatient visit; and $26,298 per hospitalization. Using the higher jungle NV incidence rates provided a lower cost per DALY of $10,135. The incremental cost per DALY with per-urban NV incidence is greater than three times the 2012 GDP per capita of Peru but the estimate drops below this threshold using the incidence from the jungle setting. In addition to the impact of incidence, sensitivity analysis showed that vaccine price and efficacy play a strong role in determining the level of cost-effectiveness.

Conclusions: The introduction of a NV vaccine would prevent many healthcare outcomes in the Peru and potentially be cost-effective in scenarios with high NV incidence. The vaccine cost-effectiveness model could also be applied to the evaluation of NV vaccine cost-effectiveness in other countries. In resource-poor settings, where NV incidence rates are expected to be higher.

Keywords: Caliciviruses; Cost-effectiveness; Diarrhea; Gastroenteritis; LMIC; Norovirus; Peru; Vaccine.

Figure 1

Markov Decision Model for Norovirus Vaccination Abbreviations: CEA – Cost-effectiveness analysis; NV - norovirus Note: Several branches have been collapsed to fit the figure (denoted with plus sign). Nodes with an ‘M’ denote a Markov process.

Figure 2

Figure 2A (top) and 2B (bottom). One-way sensitivity of Cost per Disability Adjusted Life Year (DALY) Averted versus Vaccine Cost (2A, top) and Vaccine Effectiveness (2B, bottom) using Peri-urban [6] and Jungle [15] Norovirus Incidence Rates.

Figure 3

Probabilistic Sensitivity Analysis Depicting the Proportion of the Distribution of Cost per Disability Adjusted Life Year (DALY) Averted that is Cost-Effective by a Range of Cost-Effectiveness Threshold Values, or “Willingness to Pay” (2012 USD). Note: The World Health Organization Commission on Macroeconomics and Health defines an intervention as being “very cost-effective” if it costs less than one times the gross domestic product (GDP) per capita of a country [28]. For Peru, this threshold would be represented by a Willingness to Pay (x-axis) of $6,242.