Cost-effectiveness of adult pneumococcal vaccination policies in underserved minorities aged 50-64 years compared to the US general population

A Structured Narrative Literature Review of the Broader Value of Adult Immunisation Programmes

Vaccine-preventable diseases continue to generate a substantial burden on health, healthcare systems, and societies, which is projected to increase with population ageing. There is a need to better understand the full value of adult immunisation programmes corresponding to the broader value of vaccine frameworks that are recommended for evidence-based decision-making. This review aims to summarise and map evidence for the value of selected adult immunisation programmes (seasonal influenza, pneumococcal disease, RSV, and HZ) in ten diverse countries. We conducted a structured literature review of evidence published from 2017 to 2023. An existing framework was used to structure the assessment, developing matrices demonstrating the elements of value evidenced for each vaccine and country of focus. Our analysis showed substantial evidence base on the value of adult immunisation programmes, but the availability of evidence varied by value element and by vaccine. The impact on the quality of life of the vaccinated individual was the most evidenced value element. Mortality benefits for vaccinated individuals and cost-offsets to healthcare systems were also well-evidenced. The availability of evidence for 'broader' societal value elements (such as transmission value, carer productivity and impact on social equity, and antimicrobial resistance prevention) varied. No evidence was identified relating to the broader value elements of macroeconomic effects, value to other interventions, or effects on the quality of life of caregivers. Robust evidence exists to show that adult immunisation programmes generate substantial value for population health and health systems, yet some elements of broader value remain underrepresented in the academic literature. Without such evidence, the full value of immunisation programmes is underestimated, risking suboptimal policy decisions.

Lifetime Health and Economic Burden of Invasive Pneumococcal Diseases Attributable to V116 Serotypes Among Adults in the United States

INTRODUCTION

This study aimed to estimate and compare the lifetime clinical and economic burden of invasive pneumococcal diseases (IPD) attributable to the serotypes contained in a new 21-valent pneumococcal conjugate vaccine (V116) vs. the 20-valent pneumococcal conjugate vaccine (PCV20) among adults aged 18 years and above in the USA.

METHODS

A state-transition Markov model was used to track IPD cases and deaths as well as the associated direct medical costs (in 2023 US dollars) from a US healthcare payer perspective at 3% annual discount rate. The results were summarized for V116, PCV20, and eight unique serotypes contained in V116. A sensitivity analysis was conducted to determine the most influential inputs on the overall total direct lifetime cost.

RESULTS

For the total population of US adults aged 18 years and above in 2021 (approx. 258 million residents), the estimated lifetime numbers of cases of IPD, post-meningitis sequelae (PMS), and IPD-related deaths attributable to the serotypes contained in V116 were approximately 1.4 million, 17,608, and 186,200, respectively, with a total discounted lifetime direct cost of $32.6 billion. A substantial proportion (approx. 31%) of those were attributable to the unique eight serotypes. The corresponding estimates for PCV20 were approximately 35% lower-934,000, 11,500, and 120,000, respectively-with a total discounted direct lifetime cost of $21.9 billion.

CONCLUSION

These results show that V116 serotypes (compared to PCV20) are associated with substantially higher clinical and economic burden of IPD. The addition of V116 to vaccination recommendations can help to reduce the residual burden of IPD in US adults.

Societal Cost of Racial Pneumococcal Disease Disparities in US Adults Aged 50 Years or Older

OBJECTIVE

This study aimed to estimate the societal cost of racial disparities in pneumococcal disease among US adults aged ≥  50 years.

METHODS

In a model-based analysis, societal costs of invasive pneumococcal disease (IPD) and hospitalized nonbacteremic pneumococcal pneumonia (NBP) were estimated using (1) direct medical costs plus indirect costs of acute illness; (2) indirect costs of pneumococcal mortality; and (3) direct and indirect costs of related disability. Disparities costs were calculated as differences in average per-person pneumococcal disease cost between Black and non-Black adults aged ≥  50 years multiplied by the Black population aged ≥  50 years. Costs were in 2019 US dollars (US$), with future costs discounted at 3% per year.

RESULTS

Total direct and indirect costs per IPD case were US$186,791 in Black populations and US$182,689 in non-Black populations; total hospitalized NBP costs per case were US$100,632 (Black) and US$96,781 (non-Black). The difference in population per-person total pneumococcal disease costs between Black and non-Black adults was US$47.85. Combined societal costs of disparities for IPD and hospitalized NBP totaled US$673.2 million for Black adults aged ≥  50 years. Disease and disability risks, life expectancy, and case-fatality rates were influential in one-way sensitivity analyses, but the lowest cost across all analyses was US$194 million. The 95% probability range of racial disparity costs were US$227.2-US$1156.9 million in a probabilistic sensitivity analysis.

CONCLUSIONS

US societal cost of racial pneumococcal disease disparities in persons aged ≥ 50 years is substantial. Successful pneumococcal vaccination policy and programmatic interventions to mitigate these disparities could decrease costs and improve health.

Equity-Informative Economic Evaluations of Vaccines: A Systematic Literature Review

The Immunization Agenda 2030 prioritizes the populations without access to vaccines. Health equity has been increasingly incorporated into economic evaluations of vaccines to foster equitable access. Robust and standardized methods are needed to evaluate the health equity impact of vaccination programs to ensure monitoring and effective addressing of inequities. However, methods currently in place vary and potentially affect the application of findings to inform policy decision-making. We performed a systematic review by searching PubMed, Embase, Econlit, and the CEA Registry up to 15 December 2022 to identify equity-informative economic evaluations of vaccines. Twenty-one studies were included that performed health equity impact analysis to estimate the distributional impact of vaccines, such as deaths averted and financial risk protection, across equity-relevant subgroups. These studies showed that the introduction of vaccines or improved vaccination coverage resulted in fewer deaths and higher financial risk benefits in subpopulations with higher disease burdens and lower vaccination coverage-particularly poorer income groups and those living in rural areas. In conclusion, methods to incorporate equity have been evolving progressively. Vaccination programs can enhance equity if their design and implementation address existing inequities in order to provide equitable vaccination coverage and achieve health equity.

Cost-effectiveness of revised US pneumococcal vaccination recommendations in underserved minority adults < 65-years-old

BACKGROUND

The 15- and 20-valent pneumococcal conjugate vaccines (PCV15/PCV20) were recently recommended for US adults, giving either PCV20 alone or PCV15 followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) to all 65 + -year-olds and to high-risk younger adults. However, general population recommendations to vaccinate all 50-year-olds could reduce racial pneumococcal disease disparities given greater risk in underserved minority populations.

METHODS

A Markov model examining hypothetical 50-year-old Black cohorts (serving as a proxy for underserved minorities) and non-Black cohorts estimated the incremental cost effectiveness of US adult pneumococcal vaccination recommendations compared to PCV20 or PCV15/PPSV23 for all 50-year-olds with no vaccination thereafter, or PCV20 or PCV15/PPSV23 for all at ages 50 and 65 years (50/65). Model parameters came from US databases, clinical trials, and Delphi panels. Cohorts were followed over their lifetimes from a healthcare perspective discounted at 3 %/year.

RESULTS

PCV15/PPSV23 given at ages 50/65 had greatest public health impact. In Black cohorts, PCV15/PPSV23 at age 50 cost $104,723/quality adjusted life year (QALY) gained compared to PCV20 at age 50, while PCV15/PPSV23 at 50/65 cost $240,952/QALY gained compared to PCV15/PPSV23 at age 50. Both current recommendation options were more expensive and less effective than other strategies in both cohorts. In sensitivity analyses, age-based PCV20 or PCV15/PPSV23 use at ages 50 or 50/65 could be favorable depending on vaccine effectiveness or differential vaccine uptake, while current recommendations remained unfavorable.

CONCLUSION

Recent risk-based US adult pneumococcal vaccination recommendations for adults < 65-years-old, were economically and clinically unfavorable compared to general population vaccination of all 50-year-olds in Black and non-Black cohorts. An age-based pneumococcal vaccination recommendation at age 50 years may reduce inequities in pneumococcal disease burden.

Higher-Valency Pneumococcal Conjugate Vaccines: An Exploratory Cost-Effectiveness Analysis in U.S. Seniors

INTRODUCTION

Use of the 13-valent pneumococcal conjugate vaccine in nonimmunocompromised adults aged ≥65 years is controversial. Higher-valency conjugate vaccines (15-valent and 20-valent ) are under development; their potential cost effectiveness in older adults is unknown, particularly when potential indirect (herd immunity) effects from childhood vaccination are considered.

METHODS

A Markov model estimated the cost effectiveness of current U.S. recommendations and alternative strategies using currently available and in-development pneumococcal conjugate vaccines in seniors. Separately, strategies using a hypothetical 20-valent vaccine adding the 7 most common disease-causing non-13-valent vaccine serotypes were considered. Sensitivity analyses were performed and alternative scenarios were examined. Data were gathered and the analyses were performed in 2020.

RESULTS

In analyses considering only existing and in-development vaccines, sole 20-valent vaccine use cost $172,491/quality-adjusted life year gained compared with current U.S. recommendations under baseline assumptions (equal serotype effectiveness and no childhood vaccination indirect effects). Strategies using 15-valent vaccine were more costly and less effective. When 13-valent/20-valent vaccines were assumed ineffective against pneumococcal serotype 3 and 15-valent vaccine was fully effective, 15-valent vaccine cost $237,431/quality-adjusted life year gained. With indirect effects considered, 15-valent or 20-valent vaccine cost >$449,000/quality-adjusted life year gained. When adding hypothetical 20-valent vaccine under baseline assumptions, hypothetical 20-valent vaccine cost $139,348/quality-adjusted life year gained.

CONCLUSIONS

In-development pneumococcal conjugate vaccines may be economically unreasonable in older adults, regardless of serotype effectiveness assumptions, particularly when considering potential indirect effects from use of those vaccines in children. Adult vaccines containing high-risk serotypes not contained in childhood vaccines may be more promising.

Is further research on adult pneumococcal vaccine uptake improvement programs worthwhile? Α value of information analysis

BACKGROUND

Pneumococcal vaccination policy for US adults is evolving, but previous research has shown that programs to increase vaccine uptake are economically favorable, despite parameter uncertainty. Using value of information (VOI) analysis and prior analyses, we examine the value of further research on vaccine uptake program parameters.

METHODS

In US 50-64-year-olds, current vaccine recommendations with and without an uptake program were analyzed. In older adults, current recommendations and an alternative strategy (polysaccharide vaccine for all, adding conjugate vaccine only for the immunocompromised) with and without uptake programs were examined. Uptake program parameters were derived from a clinical trial (absolute uptake increase 12.3% [range 0-25%], per-person cost $1.78 [range $0.70-$2.26]), with other parameters obtained from US databases. VOI analyses incorporated probabilistic sensitivity analysis outputs into R-based regression techniques.

RESULTS

In 50-64-year-olds, an uptake program cost $54,900/QALY gained compared to no uptake program. For ages ≥65, the program cost $287,000/QALY gained with the alternative strategy and $765,000/QALY with current recommendations. In younger adults, population-level expected value of perfect information (EVPI) was $59.7 million at $50,000/QALY gained and $2.8 million at $100,000/QALY gained. In older adults, EVPI values ranged from ~$1 million to $34.5 million at $100,000 and $200,000/QALY thresholds. The population expected value of partial perfect information (EVPPI) for combined uptake program cost and uptake improvement parameters in the younger population was $368,700 at $50,000/QALY and $43,900 at $100,000/QALY gained thresholds. In older adults, population EVPPI for vaccine uptake program parameters was $0 at both thresholds, reaching a maximum value of $445,000 at a $225,000/QALY threshold. Other model parameters comprised larger components of the global EVPI.

CONCLUSION

VOI results do not support further research on pneumococcal vaccine uptake programs in adults at commonly cited US cost-effectiveness benchmarks. Further research to reduce uncertainty in other aspects of adult pneumococcal vaccination is justifiable.

A review of health-related quality of life associated with pneumococcal disease: pooled estimates by age and type of disease

BACKGROUND

Estimates in the research literature on the health-related quality of life (QOL) associated with pneumococcal disease exhibit variation. It complicates the selection of estimates in modeling projects that evaluate the health impact and economic value of the prevention and treatment. This study reviewed the literature and developed pooled QOL estimates associated with pneumococcal disease states.

METHODS

We searched peer-reviewed literature for studies that reported pneumococcal disease-related QOL estimates. For each study, we extracted QOL estimates and categorized by age group and disease state. QOL estimates were converted to quality-adjusted life-years (QALYs). Pooled QALY estimates were calculated using simple average, sample-size weighting and inverse-variance weighting.

RESULTS

From 18 studies, we organized QOL estimates into 20 groups based on age and disease state. We observed the largest within-disease state variations of QALY estimates in meningitis-related disease states compared to other disease states. Across all age-disease state categories, the pooled QALY estimates ranged from 0.39 for meningitis with long-term sequelae among 0- to 18-year-olds, to 1.00 for non-inpatient pneumonia among 0- to 18-year-olds.

CONCLUSIONS

Our results indicated disparities in QOL estimates associated with pneumococcal disease from the literature. Pooled estimates provided a source of consistency that can be used in future modeling efforts.

Cost-Effectiveness of Pneumococcal Vaccination and Uptake Improvement Programs in Underserved and General Population Adults Aged < 65 Years

In US adults aged < 65 years, pneumococcal vaccination is recommended when high-risk conditions are present, but vaccine uptake is low. Additionally, there are race-based differences in illness risk and vaccination rates. The cost-effectiveness of programs to improve vaccine uptake or of alternative vaccination policies to increase protection is unclear. A decision analysis compared, in US black and general population cohorts aged 50 years, the public health impact and cost-effectiveness of pneumococcal vaccination recommendations, without and with a vaccine uptake improvement program, and alternative population vaccine policies. Program-based uptake improvement (base case: 12.3% absolute increase, costing $1.78/eligible patient) was based on clinical trial data. US data informed population-specific pneumococcal risk. Vaccine effectiveness was estimated using Delphi panel and trial data. In both black and general population cohorts, an uptake improvement program for current vaccination recommendations was favored, costing $48,621 per QALY gained in black populations ($54,929/QALY in the general population) compared to current recommendations without a program. Alternative vaccination policies largely prevented less illness and were economically unfavorable. In sensitivity analyses, uptake programs were favored, at a $100,000/QALY threshold, unless they improved absolute vaccine uptake < 2.1% in blacks or < 2.6% in the general population. Results were robust in sensitivity analyses. Programs to increase adult pneumococcal vaccination uptake are economically reasonable compared to changes in vaccination recommendations, and more favorable in underserved minorities than in the general population. If addressing race-based health disparities is a priority, evidence-based programs to increase vaccination should be considered.

Archetype analysis of older adult immunization decision-making and implementation in 34 countries

The global population of adults over 65 years of age is growing rapidly and is expected to double by 2050. Countries will face substantial health, economic and social burden deriving from vaccine-preventable diseases (VPDs) such as influenza, pneumonia and herpes zoster in older adults. It will be essential that countries utilize several public health strategies, including immunization. Understanding the different approaches countries have taken on adult immunization could help provide future learnings and technical support for adult vaccines within life-course immunization strategies. In this study, we describe the priorities and approaches that underlie adult immunization decision-making and implementation processes in 32 high-and-middle-income countries and two territories ("34 countries") who recommend adult vaccines in their national schedule. We conducted an archetype analysis based on a subset of two dozen indicators abstracted from a larger database. The analysis was based on a mixed-methods study, including results from 120 key informant interviews in six countries and a landscape review of secondary data from 34 countries. We found four distinct archetypes: disease prevention-focused; health security-focused; evolving adult focus; and, child-focused and cost-sensitive. The highest performing countries belonged to the disease prevention-focused and health security archetypes, although there was a range of performance within each archetype. Considering common barriers and facilitators of decision-making and implementation of adult vaccines within a primary archetype could help provide a framework for strategies to support countries with similar needs and approaches. It can also help in developing context-specific policies and guidance, including for countries prioritizing adult immunization programs in light of COVID-19. Further research may be beneficial to further refine archetypes and expand the understanding of what influences success within them. This can help advance policies and action that will improve vaccine access for older adults and build a stronger appreciation of the value of immunization amongst a variety of stakeholders.

Pneumococcal Vaccination in Adults Aged ≥65 Years: Cost-Effectiveness and Health Impact in U.S. Populations

INTRODUCTION

Recommending both the conjugate and polysaccharide pneumococcal vaccines to all U.S. seniors may have little public health impact and be economically unreasonable. Public health impact and cost-effectiveness of using both vaccines in all adults aged ≥65 years were estimated compared with an alternative strategy (omitting pneumococcal conjugate vaccine in the nonimmunocompromised) and with the newly revised recommendation (giving or omitting conjugate vaccine based on patient-physician shared decision making).

METHODS

Strategies were examined in hypothetical U.S. 65-year-old population cohorts and segmented into health states based on age- and population-specific data in a Markov state-transition model with a lifetime time horizon from a healthcare perspective. Black population cohorts were examined separately given greater illness risk and lower vaccine uptake. Model parameters came from the Centers for Disease Control Active Core Bacterial Surveillance network, National Health Interview Survey, and Nationwide Inpatient Sample data. Outcomes included incremental costs per quality-adjusted life year gained and pneumococcal disease outcomes for each strategy. Data were gathered and analysis performed in 2018.

RESULTS

Giving both vaccines, either routinely or with shared decision making, was most effective, reducing pneumococcal disease incidence compared with no vaccination, but costing $765,000-$2.18 million/quality-adjusted life year gained. Depending on examined population and scenario, the alternative strategy cost $65,700-$226,700/quality-adjusted life year gained (less in black populations) and reduced cases and deaths by 0.3%-0.9%.

CONCLUSIONS

A vaccination strategy that omits pneumococcal conjugate vaccine in immunocompetent U.S. seniors may be economically reasonable, particularly for black seniors. Use of both pneumococcal vaccines was more effective but substantially more expensive.

Age-stratified burden of pneumococcal community acquired pneumonia in hospitalised Canadian adults from 2010 to 2015

BACKGROUND

In Canada, 13-valent pneumococcal conjugate vaccine (PCV13) is recommended in childhood, in individuals at high risk of invasive pneumococcal disease (IPD) and in healthy adults aged ≥65 years for protection against vaccine-type IPD and pneumococcal community-acquired pneumonia (pCAP). Since vaccine recommendations in Canada include both age-based and risk-based guidance, this study aimed to describe the burden of vaccine-preventable pCAP in hospitalised adults by age.

METHODS

Surveillance for community-acquired pneumonia (CAP) in hospitalised adults was performed prospectively from 2010 to 2015. CAP was radiologically confirmed, and pCAP was identified using blood and sputum culture and urine antigen testing. Patient demographics and outcomes were stratified by age (16-49, 50-64, ≥65 and ≥50 years).

RESULTS

Of 6666/8802 CAP cases tested, 830 (12.5%) had pCAP, and 418 (6.3%) were attributed to a PCV13 serotype. Of PCV13 pCAP, 41% and 74% were in adults aged ≥65 and ≥50 years, respectively. Compared with non-pCAP controls, pCAP cases aged ≥50 years were more likely to be admitted to intensive care units (ICUs) and to require mechanical ventilation. Older adults with pCAP were less likely to be admitted to ICU or required mechanical ventilation, given their higher mortality and goals of care. Of pCAP deaths, 67% and 90% were in the ≥65 and ≥50 age cohorts, respectively.

CONCLUSIONS

Adults hospitalised with pCAP in the age cohort of 50-64 years contribute significantly to the burden of illness, suggesting that an age-based recommendation for adults aged ≥50 years should be considered in order to optimise the impact of pneumococcal vaccination programmes in Canada.

Cost-Effectiveness of Pneumococcal Vaccination Policies and Uptake Programs in US Older Populations

BACKGROUND/OBJECTIVES

Recently revised vaccination recommendations for US adults, aged 65 years and older, include both 23-valent pneumococcal polysaccharide vaccine (PPSV23) and 13-valent pneumococcal conjugate vaccine (PCV13), with PCV13 now recommended for immunocompetent older people based on shared decision making. The public health impact and cost-effectiveness of this recommendation or of pneumococcal vaccine uptake improvement interventions are unclear.

DESIGN

Markov decision analysis.

SETTING AND PARTICIPANTS

Hypothetical 65-year-old general and black population cohorts.

INTERVENTION

Current pneumococcal vaccination recommendations for US older people, an alternative policy omitting PCV13 in immunocompetent older people, and vaccine uptake improvement programs.

RESULTS

The current pneumococcal vaccination recommendation was the most effective strategy, but afforded slight public health benefits compared to an alternative (PPSV23 for all older people plus PCV13 for the immunocompromised) and cost greater than $750 000 per quality-adjusted life-year (QALY) gained in either population group with a vaccine uptake improvement program (absolute uptake increase = 12.3%; cost = $1.78/eligible patient) in place. The alternative strategy was more economically favorable, but cost greater than $100 000/QALY in either population, with or without an uptake intervention. Results were robust in sensitivity analyses; however, in black older people, the alternative strategy with an uptake program was most likely to be favored in probabilistic sensitivity analyses at a $150 000/QALY gained threshold.

CONCLUSION

Current pneumococcal vaccination recommendations for US older people are economically unfavorable compared to an alternative strategy omitting PCV13 in the immunocompetent. The alternative recommendation with an uptake improvement program may be economically reasonable in black population analyses and could be worth considering as a population-wide recommendation if mitigating racial disparities is a priority. J Am Geriatr Soc 68:1271-1278, 2020.