Results from a study published in CMAJ found that vaccines against herpes zoster are effective for people aged ≥50 years; however, the recombinant subunit zoster vaccine was found to be more cost-effective than the live attenuated zoster vaccine.
Researchers used a decision analytic static cohort model that compared the incidence of herpes zoster and postherpetic neuralgia, mortality rate, use of health care resources, costs, and quality-adjusted life-years (QALY) lost between vaccinated and unvaccinated adults. The researchers conducted a systematic review of literature and data extraction from Quebec administrative databases to identify epidemiologic parameters and health care use associated with herpes zoster, as well as costs related to herpes zoster and postherpetic neuralgia.
Outcomes of the study included prevaccination burden of herpes zoster in Canada, effectiveness of herpes zoster vaccination, and cost-effectiveness of herpes zoster vaccination.
The researchers predicted that 90,623 cases of herpes zoster, 13,575 cases of ophthalmic herpes zoster, and 17,502 cases of postherpetic neuralgia would occur among adults aged ≥50 years in Canada, with the highest burden of disease occurring in those aged ≥70 years. The number needed to vaccinate was higher for the live attenuated zoster vaccine than for the recombinant subunit zoster vaccine for all herpes zoster-related events at all ages. The difference in the number needed to vaccinate between the vaccines increased with increasing age for the live vaccine but not for the recombinant vaccine.
Administration of the vaccine in adults aged 65 to 75 years was predicted to result in cost-effective ratios below $45,000 per QALY gained for both vaccines and under all scenarios. For the recombinant vaccine, the median cost-effectiveness ratio predictions varied between cost-saving and $25,881 per QALY gained. For those aged ≥60 years, the cost-effectiveness ratios remained stable. For the live vaccine, the median cost-effectiveness ratio predictions varied between cost saving and $130,587 per QALY gained. The cost-effectiveness ratios for the live vaccine were highly sensitive to age at vaccination but remained below $45,000 per QALY gained for those between 65 and 75 years of age.
The recombinant vaccine was estimated to be more cost-effective than the live vaccine for all ages at vaccination. Depending on the age at vaccination, the cost for the complete series of the recombinant vaccine could be $150 to $200 more than for the live vaccine and still be considered cost-effective.
“Our modelling analysis suggests that vaccination against herpes zoster is most likely a cost-effective intervention in Canada,” the authors concluded. “However, vaccination with the recombinant subunit zoster vaccine is predicted to provide greater effectiveness for all age groups and is likely to be more cost-effective than the live attenuated zoster vaccine.”
Drolet M, Zhou Z, Sauvageau C, et al. Effectiveness and cost-effectiveness of vaccination against herpes zoster in Canada: a modelling study. CMAJ. 2019;191:E932-E939.