Determining the Optimal Vaccination Schedule for Herpes Zoster: a Cost-Effectiveness Analysis

Clinical and economic implications of increasing access to herpes zoster vaccination rate in community pharmacies

BACKGROUND

A community pharmacist plays an important role in providing vaccination to the general public in the United States. No economic models have been used to assess the impact of these services on public health and economic benefits.

OBJECTIVE

This study aimed to estimate the clinical and economic implications of community pharmacy-based herpes zoster (HZ) vaccination services with a hypothetical scenario of nonpharmacy-based vaccination in the State of Utah.

METHODS

A hybrid model of decision tree and Markov models was used to estimate lifetime cost and health outcomes. This open-cohort model was populated based on Utah population statistics and included a population of 50 years and older who were eligible for HZ vaccination between the years 2010 and 2020. Data were derived from the U.S. Bureau of Labor Statistics, the Utah Immunization Coverage Report, the Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System, the CDC National Health Interview Survey, and existing literature. The analysis was performed from a societal perspective. A lifetime time horizon was used. The primary outcomes were the number of vaccination cases increased and the number of shingles and postherpetic neuralgia (PHN) cases averted. Total costs and quality-adjusted life-years (QALYs) were also estimated.

RESULTS

Based on a cohort of 853,550 people eligible for HZ vaccination in Utah, an additional 11,576 individuals were vaccinated in the community pharmacy-based scenario compared with the nonpharmacy-based vaccination, resulting in 706 averted cases of shingles and 143 averted cases of PHN. Community pharmacy-based HZ vaccination was less costly (-$131,894) and gained more QALYs (52.2) compared with the nonpharmacy-based vaccination. A series of sensitivity analyses showed that the findings were robust.

CONCLUSIONS

Community pharmacy-based HZ vaccination was less costly and gained more QALYs and was associated with improved other clinical outcomes in the State of Utah. This study might be used as a model for future evaluations of other community pharmacy-based vaccination programs in the United States.

Cost-effectiveness of herpes zoster vaccines in the U.S.: A systematic review

The purpose of this study was to conduct a systematic review to evaluate the cost-effectiveness evidence of herpes zoster vaccines in the U.S. A systematic literature review was undertaken for U.S. studies focused on the cost-effectiveness of herpes zoster vaccines. Eligibility criteria included studies that evaluated the cost-effectiveness of the recombinant zoster vaccine (RZV) and zoster vaccine live (ZVL) and were published between 2015 and 2021. Article titles and abstracts were reviewed to identify relevant publications. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) criteria for economic evaluations were used to evaluate the studies. Eleven published studies met inclusion and exclusion criteria. Seven studies compared RZV and ZVL. Four studies compared ZVL dosing regimens with or without a no vaccine option. All studies incorporated health system costs. Ten out of eleven (90.9%) studies conducted their analyses from a societal perspective and included indirect costs. For measurements of effectiveness, ten of eleven (90.9%) studies estimated quality-adjusted life years, four (36.4%) used shingles cases averted, two (18.2%) employed deaths prevented, and one (9.1%) measured life years saved. All studies that compared RZV with no vaccine found RZV to be a cost-effective strategy to prevent both shingles and post-herpetic neuralgia. Additionally, these analyses showed that RZV consistently dominated ZVL. Compliance with the second RZV dose was important for full benefit of the vaccine. The studies identified in this systematic review identified well-constructed cost-effectiveness analyses of herpes zoster vaccines in the U.S. RZV was more cost-effective than no vaccine or ZVL. This systematic review supports removal of ZVL from the U.S. market.

Using Social Media to Engage Knowledge Users in Health Research Priority Setting: Scoping Review

BACKGROUND

The need to include individuals with lived experience (ie, patients, family members, caregivers, researchers, and clinicians) in health research priority setting is becoming increasingly recognized. Social media-based methods represent a means to elicit and prioritize the research interests of such individuals, but there remains sparse methodological guidance on how best to conduct these social media efforts and assess their effectiveness.

OBJECTIVE

This review aims to identify social media strategies that enhance participation in priority-setting research, collate metrics assessing the effectiveness of social media campaigns, and summarize the benefits and limitations of social media-based research approaches, as well as recommendations for prospective campaigns.

METHODS

We searched PubMed, Embase, Cochrane Library, Scopus, and Web of Science from database inception until September 2021. Two reviewers independently screened all titles and abstracts, as well as full texts for studies that implemented and evaluated social media strategies aimed at engaging knowledge users in research priority setting. We subsequently conducted a thematic analysis to aggregate study data by related codes and themes.

RESULTS

A total of 23 papers reporting on 22 unique studies were included. These studies used Facebook, Twitter, Reddit, websites, video-calling platforms, emails, blogs, e-newsletters, and web-based forums to engage with health research stakeholders. Priority-setting engagement strategies included paid platform-based advertisements, email-embedded survey links, and question-and-answer forums. Dissemination techniques for priority-setting surveys included snowball sampling and the circulation of participation opportunities via internal members' and external organizations' social media platforms. Social media campaign effectiveness was directly assessed as number of clicks and impressions on posts, frequency of viewed posts, volume of comments and replies, number of times individuals searched for a campaign page, and number of times a hashtag was used. Campaign effectiveness was indirectly assessed as numbers of priority-setting survey responses and visits to external survey administration sites. Recommendations to enhance engagement included the use of social media group moderators, opportunities for peer-to-peer interaction, and the establishment of a consistent tone and brand.

CONCLUSIONS

Social media may increase the speed and reach of priority-setting participation opportunities leading to the development of research agendas informed by patients, family caregivers, clinicians, and researchers. Perceived limitations of the approach include underrepresentation of certain demographic groups and addressing such limitations will enhance the inclusion of diverse research priority opinions in future research agendas.

Incremental net monetary benefit of herpes zoster vaccination: a systematic review and meta-analysis of cost-effectiveness evidence

OBJECTIVES

To perform a systematic review and meta-analysis to pool the incremental net benefit (INB) of each herpes zoster vaccine [i.e. Zoster Vaccine Live (ZVL) and Recombinant Zoster Vaccine (RZV)].

METHODS

We initially identified individual studies by hand-searching reference lists of the relevant systematic review articles. An updated comprehensive search was performed in Medline, Scopus, and Embase until June 2020 for additional studies. Studies were eligible if they assessed the cost-effectiveness/utility of any pair among ZVL and RZV, and no vaccine and reported economic outcomes. Details of the study characteristics, economic model inputs, costs, and outcomes were extracted. INB was calculated with monetary units adjusting for purchasing power parity for 2019 US dollars and pooled by meta-analysis.

RESULTS

A total of 37 studies were pooled for meta-analysis stratified by perspectives [i.e. societal (SP) and third-party payer (TPP)] and vaccine types. In SP, ZVL was cost-effective compared to no vaccine when vaccinated at ages of 50-59 and 70-79 years with INBs (95% CI) of $0.61 (0.37, 0.85) and $9.67 (5.20, 14.14), respectively. RZV was cost-effective for those aged 60-69 and 70-79 years with INBs of $75.61 (17.98, 133.23) and $85.01 (30.02, 140.01), respectively. In TPP, ZVL was cost-effective compared to no vaccine when vaccinated at age 70-79 years with INB of $7.57 (0.27, 14.86) and RZV was cost-effective at 60-69 years with INB $220.87 (47.80, 393.93). The cost-effectiveness of RZV was robust across a series of sensitivity analyses, but ZVL differs on different vaccination ages.

CONCLUSIONS

RZV may be cost-effective for vaccination in ages of 60-79 years for both SP and TPP perspectives, while ZVL might be cost-effective in some age groups, but results are not robust.

Varicella zoster virus vaccines: an update

Varicella zoster virus (VZV) is the etiological agent of varicella, a highly infectious, self-limiting disease with serious complications. The decline in cell-mediated immunity (CMI) that occurs with aging or immunodepression causes a reactivation of the latent VZV as herpes zoster (HZ). Prevention of VZV through varicella vaccination strategies allows to avoid the primary infection in newborns and susceptible subjects. Available monovalent and combined VZV vaccines are effective, safe and generally well tolerated. Universal varicella vaccination has significantly impacted on incidence, complications and deaths related to this disease. Prevention of HZ through vaccination is a priority to avoid the significant burden of its incidence and complications. Currently two HZ vaccines are available. The recombinant zoster vaccine (RZV), approved by the FDA in 2017 and Zoster Vaccine Live (ZVL) licensed in the United States by the FDA in 2006. The advisory committee on immunization practices (ACIP) preferentially recommends RZV. ZVL remains an option for prevention of HZ in immunocompetent adults aged ≥60 years, although the CMI tends to wane a few years after vaccination.

Cost-Effectiveness of Herpes Zoster Vaccination: A Systematic Review

BACKGROUND

Herpes zoster (HZ) is one of the most common diseases among adults. Its reactivation is characterized by a severe and painful complication. In addition to the existing herpes zoster vaccine (ZVL), the FDA approved a new adjuvanted subunit zoster vaccine (RZV) in 2017 for use in adults aged 50 years and older. Several studies have assessed the cost-effectiveness of ZVL, many of which were conducted before the long-term vaccine  efficacy data was available in 2014.

OBJECTIVE

Our objectives were to (i) summarize and compare the cost-effectiveness analyses (CEAs) of ZVL conducted before and after 2014, (ii) summarize the CEAs of RZV, and (iii) critically assess the cost-effectiveness models and identify key parameters to consider for future CEAs of RZV.

METHODS

We searched PubMed and two other databases from inception to March 2018 for original cost-effectiveness, cost-utility, or cost-benefit analyses of HZ vaccines. Three investigators independently reviewed and assessed full-text articles after screening the titles and abstracts to determine eligibility. For all included studies, we assessed study quality using the Drummond and Jefferson's checklist and extracted study characteristics, model structure, vaccine characteristics, incidence of HZ and complications, incremental cost-effectiveness ratio, and sensitivity analyses. We summarized data by type of vaccine, year of publication, and funding sources.

RESULTS

Twenty-seven studies met eligibility criteria. All studies were from high-income countries and were of moderate-to-high or high quality. Twenty studies repeatedly used four cost-effectiveness models. The assumption on long-term efficacy of ZVL was not based on clinical trial data in > 50% of studies. Fifteen out of 25 studies concluded that ZVL was cost-effective compared with no vaccine at a vaccine price ranging between US$93 and US$236 per dose (2018 US$), 40% of which were published after 2014. All industry-funded studies favored the use of ZVL. The single study assessing RZV found it to be more effective and less costly than ZVL, and cost-effective compared with no vaccination. More studies conducted after 2014 included various efficacy endpoints for ZVL, adverse reactions, and productivity loss compared with those conducted before 2014.

CONCLUSIONS

A majority of studies of ZVL found it to be cost-effective compared with no vaccine using the authors' chosen willingness-to-pay thresholds. RZV was dominant in the single study comparing the two vaccines, but the finding needs to be confirmed with further studies in different settings. Future studies should assume vaccine efficacy in line with clinical data, account for more efficacy endpoints for ZVL, and include other HZ long-term complications, vaccine adverse reactions, and productivity loss.

Cost-effectiveness of adult vaccinations: A systematic review

BACKGROUND

Coverage levels for many recommended adult vaccinations are low. The cost-effectiveness research literature on adult vaccinations has not been synthesized in recent years, which may contribute to low awareness of the value of adult vaccinations and to their under-utilization. We assessed research literature since 1980 to summarize economic evidence for adult vaccinations included on the adult immunization schedule.

METHODS

We searched PubMed, EMBASE, EconLit, and Cochrane Library from 1980 to 2016 and identified economic evaluation or cost-effectiveness analysis for vaccinations targeting persons aged ≥18 years in the U.S. or Canada. After excluding records based on title and abstract reviews, the remaining publications had a full-text review from two independent reviewers, who extracted economic values that compared vaccination to "no vaccination" scenarios.

RESULTS

The systematic searches yielded 1688 publications. After removing duplicates, off-topic publications, and publications without a "no vaccination" comparison, 78 publications were included in the final analysis (influenza = 25, pneumococcal = 18, human papillomavirus = 9, herpes zoster = 7, tetanus-diphtheria-pertussis = 9, hepatitis B = 9, and multiple vaccines = 1). Among outcomes assessing age-based vaccinations, the percent indicating cost-savings was 56% for influenza, 31% for pneumococcal, and 23% for tetanus-diphtheria-pertussis vaccinations. Among age-based vaccination outcomes reporting $/QALY, the percent of outcomes indicating a cost per QALY of ≤$100,000 was 100% for influenza, 100% for pneumococcal, 69% for human papillomavirus, 71% for herpes zoster, and 50% for tetanus-diphtheria-pertussis vaccinations.

CONCLUSIONS

The majority of published studies report favorable cost-effectiveness profiles for adult vaccinations, which supports efforts to improve the implementation of adult vaccination recommendations.

Primary care physicians' experience with zoster vaccine live (ZVL) and awareness and attitudes regarding the new recombinant zoster vaccine (RZV)

BACKGROUND

The Advisory Committee on Immunization Practices (ACIP) has routinely recommended zoster vaccine live (ZVL) for adults  ≥60 since 2008; only 33% of eligible adults received it by 2016. A recombinant zoster vaccine (RZV) was licensed in 2017 and ACIP recommended in January 2018. Our objectives were to assess among primary care physicians (1) practices and attitudes regarding ZVL and (2) awareness of RZV.

METHODS

We administered an Internet and mail survey from July to September 2016 to national networks of 953 primary care physicians.

RESULTS

Response rate was 65% (603/923). Ninety-three % of physicians recommended ZVL to adults ≥60, but fewer recommended it to adults ≥60 with a prior history of zoster (88%), adults > 85 (62%) and adults ≥60 on low-dose methotrexate (42%). Several physicians recommended ZVL in ways that are not recommended by ACIP including to adults 50-59 (50%), adults ≥60 with HIV (33%), and adults ≥60 on high dose prednisone (≥20 mg/day) (27%). Nineteen percent of physicians stocked and administered ZVL and did not refer patients elsewhere for vaccination, 37% did not stock and only referred patients to receive it, and 44% both stocked/administered and referred elsewhere. Twenty-three % (n = 115) of physicians who had ever administered ZVL in the office (n = 490) had stopped, citing primarily financial issues (90%). Only 5% were 'very aware' of RZV.

CONCLUSIONS

Physicians report not recommending ZVL to certain ACIP-recommended groups, but report recommending it to some groups for which the vaccine should be avoided. Implementation of recommendations for RZV will need to consider financial barriers and the complex patchwork of office-based and pharmacy delivery ZVL has encountered.

Cost-effectiveness of the Adjuvanted Herpes Zoster Subunit Vaccine in Older Adults

IMPORTANCE

The live attenuated herpes zoster vaccine (ZVL) is recommended for immunocompetent adults 60 years or older, but the efficacy wanes with age and over time. A new adjuvanted herpes zoster subunit vaccine (HZ/su) has higher efficacy but might be more expensive. The choice of vaccines depends on their relative values.

OBJECTIVE

To assess the cost-effectiveness of HZ/su.

DESIGN, SETTING, AND PARTICIPANTS

Markov decision model with transition probabilities based on the US medical literature. Participants were immunocompetent adults 60 years or older. Data were derived from participant groups ranging in number from less than 100 to more than 30 000 depending on the variable assessed. The study dates were July 1 to 31, 2017.

EXPOSURES

No vaccination, ZVL (single dose), and HZ/su (2-dose series) vaccine administered at different ages.

MAIN OUTCOMES AND MEASURES

Total costs and quality-adjusted life-years (QALYs) were estimated.

RESULTS

Based on randomized clinical trial data, at a price of $280 per series ($140 per dose), HZ/su was more effective and less expensive than ZVL at all ages. The incremental cost-effectiveness ratios compared with no vaccination ranged from $20 038 to $30 084 per QALY, depending on vaccination age. The finding was insensitive to variations in most model inputs other than the vaccine price and certain combinations of low adherence rate with a second dose and low efficacy of a single dose of HZ/su. At the current ZVL price ($213 per dose), HZ/su had lower overall costs than ZVL up to a price of $350 per 2-dose series. In probabilistic sensitivity analysis, HZ/su had 73% probability of being cost-effective for 60-year-olds at $50 000 per QALY.

CONCLUSIONS AND RELEVANCE

Under conservative assumptions, at a price of $280 per series ($140 per dose), HZ/su would cost less than ZVL and has a high probability of offering good value.

Cost Effectiveness of a Shingles Vaccine Booster for Currently Vaccinated Adults in the U.S

INTRODUCTION

The Advisory Committee on Immunization Practices recommends a single dose of the live attenuated herpes zoster vaccine in people aged ≥60 years. Because vaccine-induced protection decreases to zero after 10 years, many vaccinated people will soon be subject to an increased risk of the disease. The study objective was to determine the cost effectiveness of a herpes zoster vaccine booster and its optimal timing among immunocompetent adults first vaccinated at aged ≥60 years.

METHODS

A Markov model was built to follow vaccinated individuals for a lifetime. From the societal perspective, costs and quality-adjusted life years were compared between no booster versus booster options. A booster was given any time between 1 and 20 years after the first dose, and for those who had the first dose at different ages: 60, 70, and 80 years. Because people entered the model already vaccinated, costs and side effects of the first dose were not included. The booster was assumed to have the same efficacy and waning rate as the initial vaccination. Model inputs were based on published literature. A cost effectiveness threshold of $100,000/quality-adjusted life year was used. The analysis was conducted in 2016.

RESULTS

Cost effectiveness of a booster varied by age and time since vaccination. The booster cost <$100,000/quality-adjusted life year if given >5 years after the initial dose, but was most cost effective at around 10 years. The finding was robust to wide variations in model inputs.

CONCLUSIONS

Under current assumptions, a booster dose of herpes zoster vaccine would be cost effective for all vaccinated people 10 years after initial vaccination.

Varicella and herpes zoster vaccine development: lessons learned

INTRODUCTION

Before vaccination, varicella zoster virus (VZV), which is endemic worldwide, led to almost universal infection. This neurotropic virus persists lifelong by establishing latency in sensory ganglia, where its reactivation is controlled by VZV-specific T-cell immunity. Lifetime risk of VZV reactivation (zoster) is around 30%. Vaccine development was galvanised by the economic and societal burden of VZV, including debilitating zoster complications that largely affect older individuals. Areas covered: We describe the story of development, licensing and implementation of live attenuated vaccines against varicella and zoster. We consider the complex backdrop of VZV virology, pathogenesis and immune responses in the absence of suitable animal models and examine the changing epidemiology of VZV disease. We review the vaccines' efficacy, safety, effectiveness and coverage using evidence from trials, observational studies from large routine health datasets and clinical post-marketing surveillance studies and outline newer developments in subunit and inactivated vaccines. Expert commentary: Safe and effective, varicella and zoster vaccines have already made major inroads into reducing the burden of VZV disease globally. As these live vaccines have the potential to reactivate and cause clinical disease, developing alternatives that do not establish latency is an attractive prospect but will require better understanding of latency mechanisms.