A Cost-effectiveness Analysis of an Adjuvanted Subunit Vaccine for the Prevention of Herpes Zoster and Post-herpetic Neuralgia.

BACKGROUND

Herpes zoster (HZ) develops in up to 50% of unvaccinated individuals, accounting for >1 million cases annually in the United States. A live attenuated HZ vaccine (LAV) is Food and Drug Administration approved for those age 50 years or older, though Advisory Committee on Immunization Practices recommendations are only for those age 60 years or older. LAV efficacy is ~70% for persons 50-59 years of age, with lower efficacy in older adults. A new 2-dose adjuvanted subunit vaccine (SUV) has >95% efficacy in persons 50-69 years of age and remains ~90% efficacious in persons vaccinated at age 70 years.

METHODS

To estimate the relative cost-effectiveness of SUV, LAV, and no vaccination (NoV) strategies, a Markov model was developed based on published data on vaccine efficacy, durability of protection, quality of life, resource utilization, costs, and disease epidemiology. The perspective was US societal, and the cycle length was 1 year with a lifelong time horizon. SUV efficacy was estimated to wane at the same rate as LAV. Outcomes evaluated included lifetime costs, discounted life expectancy, and incremental cost-effectiveness ratios (ICERs).

RESULTS

For individuals vaccinated at age 50 years, the ICER for LAV vs NoV was $118 535 per quality-adjusted life-year (QALY); at age 60 years, the ICER dropped to $42 712/QALY. SUV was more expensive but had better ICERs than LAV. At age 50, the ICER was $91 156/QALY, and it dropped to $19 300/QALY at age 60.

CONCLUSIONS

Vaccination with SUV was more cost-effective than LAV in all age groups studied. Vaccination with SUV at age 50 years appears cost-effective, with an ICER <$100 000/QALY.