Effectiveness and cost-effectiveness of vaccination against herpes zoster in Canada: a modelling study

Abstract

H erpes zoster, characterized by dermatomal pain and rash, 1,2 affects about 1 of every 3 persons during their lifetime. 3-5 The most common complication is longlasting debilitating pain, known as postherpetic neuralgia, which occurs in about 8% to 27% of individuals with herpes zoster. 6-10 Given that postherpetic neuralgia has a substantial negative impact on health-related quality of life 11 and that therapeutic options are only partially effective, 12 the best option remains the prevention of herpes zoster and thus postherpetic neuralgia. 13 Two herpes zoster vaccines are currently authorized for use in Canada among adults aged 50 years or older: the recombinant subunit zoster vaccine (Shingrix) and the live attenuated zoster vaccine (Zostavax). The recombinant vaccine was approved recently (October 2017), whereas the live vaccine has been available since 2008. Clinical trials have shown that the recombinant vaccine is highly effective against herpes zoster and postherpetic neuralgia for adults aged 50 years or older (vaccine efficacy against herpes zoster 96.6% for those 50-59 yr and 97.9% for those > 70 yr) with no evidence of waning protection after 4 years. 14 Recent immunogenicity data also suggest that the immune response is maintained up to 9 years after vaccination. 15 Conversely, clinical trials and observational data have suggested that the efficacy of the live vaccine against herpes zoster decreases with older age at vaccination (from 65.5% for those 60-69 yr to 55.4% for those ≥ 70 yr 10) and wanes with increasing time since vaccination. 16-18 Although the recombinant vaccine appears to be more effective, particularly among older adults, a 2-dose schedule is recommended, compared with a 1-dose schedule for the live vaccine; this difference has implications for costs and vaccination logistics. Furthermore, although both vaccines have been shown to be safe, a significantly higher proportion of adults vaccinated RESEARCH HEALTH SERVICES

Cost-effectiveness of varicella and herpes zoster vaccination in Sweden: An economic evaluation using a dynamic transmission model

“…This put forward that in a situation where we have reached a steady state after vaccine implementation, the cost per gained QALY would be much lower than in the implementation phase of the vaccination programme. The steady state results were in line with previous studies [ 60 ]. The results from the sensitivity analysis indicate a more favourable cost per gained QALY if vaccination against herpes zoster would target 75-year-olds, rather than 65-year-olds.…”

Cost-effectiveness of the recombinant zoster vaccine (RZV) against herpes zoster: An updated critical review

“…Manual search of the public health online repositories mentioned in the Study Selection revealed four additional studies. 16–19 Two 16 , 17 were deemed equivalent to Drolet et al 20 and were excluded from further review.…”

Impact of a Publicly Funded Herpes Zoster Immunization Program on the Burden of Disease in Ontario, Canada: A Population-based Study

“…Specifically, expanding public funding to include the HZ/su vaccine would address the limitations of ZVL, including waning efficacy with age and time and a contraindication for use in immunosuppressed individuals at greatest risk of varicella zoster reactivation and severe herpes zoster–related complications [ 5 , 28 , 29 ]. This assertion is supported by a comparison of the cost-effectiveness of HZ/su and ZVL from the perspective of the Canadian health care system, in that HZ/su was more cost-effective and associated with a lower number needed to vaccinate (number of people who should be vaccinated to prevent a single case of herpes zoster, postherpetic neuralgia, ophthalmic herpes zoster, and hospitalization) than ZVL [ 30 ]. Although HZ/su is most cost-effective among adults aged 65 to 79 years, findings were consistent across all age groups, suggesting that broadening eligibility of a publicly funded HZ/su vaccination program to encompass all individuals over the age of 50 could optimize the public health impact of such an approach.…”