Respiratory syncytial virus knowledge, attitudes, and perceptions among adults in the United States

Respiratory syncytial virus (RSV) is associated with considerable morbidity and mortality among older adults (aged ≥60 years) and adults with certain chronic conditions in the United States (US). Despite this burden, no previous studies have assessed the knowledge, attitudes, and perceptions (KAP) of RSV among these populations. This study evaluates RSV-related KAP among US adults at increased risk of severe RSV infection. A cross-sectional, web-based survey was administered from May to June 2022 to better understand respiratory infection- and RSV-related KAP among US adults who are at risk of severe RSV infection. The survey included ≥200 adults in each of 4 subgroups: adults aged 60-89 years, and adults aged 18-59 years with ≥1 chronic cardiovascular condition, chronic pulmonary condition, or diabetes mellitus. Survey responses were analyzed descriptively overall and by subgroup, with exploratory logistic regression modeling used to evaluate characteristics associated with RSV awareness and concern. Among the 827 survey respondents, only 43.3% had ever heard of RSV (n = 358/827). The study identified key knowledge gaps (e.g. bacterial vs. viral nature of respiratory infections, RSV seasonality, common RSV symptoms, extent to which RSV causes respiratory infections in specific patient populations). Although 33.7% of RSV-aware adults (n = 120/356) reported being worried/very worried about RSV, 67.3% (n = 241/358) rarely consider RSV as a potential cause of their cold/flu-like symptoms. Results from this study highlight important knowledge gaps related to RSV, perceived risk, and severity of RSV. Findings can be used to support the development of tailored education efforts to support RSV prevention.

Public Health Impact of the Adjuvanted RSVPreF3 Vaccine for Respiratory Syncytial Virus Prevention Among Older Adults in the United States

INTRODUCTION

Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract disease in older adults, resulting in substantial morbidity and mortality.

METHODS

This study estimates the public health impact of vaccination with the adjuvanted RSVPreF3 vaccine among adults aged ≥ 60 years in the United States (US). A static, multi-cohort Markov model was used to estimate RSV-related outcomes over a 3-year time horizon for scenarios with and without one-time RSV vaccination. The base-case analysis assumed the same vaccination coverage as for influenza vaccines, with key epidemiology and vaccine inputs obtained from the published literature and phase 3 clinical trial results for the adjuvanted RSVPreF3 vaccine. Model outcomes included the clinical burden of RSV (symptomatic RSV acute respiratory illness [RSV-ARI] cases [classified as upper or lower respiratory tract disease], pneumonia complications, and mortality) and RSV-related healthcare resource use (hospitalizations, emergency department visits, outpatient visits, and antibiotic prescriptions).

RESULTS

In the base-case analysis, approximately 56.7 million adults aged ≥ 60 years received the vaccine, resulting in 2,954,465 fewer symptomatic RSV-ARI cases over 3 years compared with no vaccination, including 321,019 fewer X-ray confirmed pneumonia cases and 16,660 fewer RSV-related deaths. Vaccination also prevented a substantial number of RSV-related hospitalizations (203,891), emergency department visits (164,060), outpatient visits (1,577,586), and antibiotic prescriptions (1,343,915) over the 3-year period. A considerable public health impact was observed across a range of sensitivity analyses.

CONCLUSIONS

These findings highlight the potential of the adjuvanted RSVPreF3 vaccine to substantially reduce RSV disease burden among US older adults aged ≥ 60 years.

Public health impact of recombinant zoster vaccine for prevention of herpes zoster in US adults immunocompromised due to cancer

Individuals who are immunocompromised (IC) due to therapy or underlying disease are at increased risk of herpes zoster (HZ). This study evaluates the public health impact of recombinant zoster vaccine (RZV) relative to no HZ vaccination for the prevention of HZ among adults aged ≥18 years diagnosed with selected cancers in the United States (US). A static Markov model was used to simulate three cohorts of individuals who are IC with cancer (time horizon of 30 years; one-year cycle length): hematopoietic stem cell transplant (HSCT) recipients, patients with breast cancer (BC; a solid tumor example), and patients with Hodgkin's lymphoma (HL; a hematological malignancy example). Cohort sizes reflect the estimated annual incidence of each condition in the US population (19,671 HSCT recipients, 279,100 patients with BC, and 8,480 patients with HL). Vaccination with RZV resulted in 2,297; 38,068; and 848 fewer HZ cases for HSCT recipients, patients with BC, and patients with HL, respectively (each versus no vaccine). Vaccination with RZV also resulted in 422; 3,184; and 93 fewer postherpetic neuralgia cases for HSCT, BC, and HL, respectively. Analyses estimated the quality-adjusted life years gained to be 109, 506, and 17 for HSCT, BC, and HL, respectively. To prevent one HZ case, the number needed to vaccinate was 9, 8, and 10, for HSCT, BC, and HL, respectively. These results suggest RZV vaccination may be an effective option to significantly reduce HZ disease burden among patients diagnosed with selected cancers in the US.

Cost-Effectiveness of Recombinant Zoster Vaccine for the Prevention of Herpes Zoster in Hematopoietic Stem Cell Transplant Recipients and Other Immunocompromised Adults in the United States

INTRODUCTION

Immunocompromised (IC) adults are at increased risk of developing herpes zoster (HZ) and HZ-related complications due to therapy or underlying disease. This study evaluated the cost effectiveness of recombinant zoster vaccine (RZV) versus no vaccine for the prevention of HZ in hematopoietic stem cell transplant (HSCT) recipients and other IC adults aged ≥ 18 years in the United States (US).

METHODS

A static Markov model simulated cohorts of IC individuals using a 1-year cycle length and 30-year time horizon to estimate the cost effectiveness of RZV. Inputs were sourced from clinical trial results and publicly available sources/literature. Modeled populations included US adult HSCT recipients (base case), patients with human immunodeficiency virus (HIV), patients with breast cancer, patients with Hodgkin's lymphoma, and renal transplant recipients. The model reported societal costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). Sensitivity and threshold analyses were conducted.

RESULTS

In the base case of 19,671 US adult HSCT recipients, RZV resulted in total societal cost savings of US$0.1 million and 109 incremental QALYs versus no vaccine. RZV was a 'dominant strategy' versus no vaccine because vaccination resulted in cost savings with QALY gains. RZV was also cost saving in renal transplant recipients, and cost effective at a willingness-to-pay threshold of US$100,000 per QALY gained in patients with HIV, breast cancer, and Hodgkin's lymphoma, with ICERs of US$33,268, US$67,682, and US$95,972 per QALY gained, respectively, versus no vaccine.

CONCLUSIONS

Model results show RZV is potentially cost saving for the prevention of HZ in US adult HSCT recipients and US adults with selected immunocompromising conditions, and cost effective for others, supporting the use of RZV to prevent HZ and HZ-related complications in IC adults.

Value of the Immunization Program for Children in the 2017 US Birth Cohort

BACKGROUND AND OBJECTIVES

We evaluated the economic impact of routine childhood immunization in the United States, reflecting updated vaccine recommendations and recent data on epidemiology and coverage rates.

METHODS

An economic model followed the 2017 US birth cohort from birth through death; impact was modeled via a decision tree for each of the vaccines recommended for children by the Advisory Committee on Immunization Practices as of 2017 (with annual influenza vaccine considered in scenario analysis). Using information on historic prevaccine and vaccine-era incidence and disease costs, we calculated disease cases, deaths, disease-related healthcare costs, and productivity losses without and with vaccination, as well as vaccination program costs. We estimated cases and deaths averted because of vaccination, life-years and quality-adjusted life-years gained because of vaccination, incremental costs (2019 US dollars), and the overall benefit-cost ratio (BCR) of routine childhood immunization from the societal and healthcare payer perspectives.

RESULTS

Over the cohort's lifetime, routine childhood immunization prevented over 17 million cases of disease and 31 000 deaths; 853 000 life years and 892 000 quality-adjusted life-years were gained. Estimated vaccination costs ($8.5 billion) were fully offset by the $63.6 billion disease-related averted costs. Routine childhood immunization was associated with $55.1 billion (BCR of 7.5) and $13.7 billion (BCR of 2.8) in averted costs from a societal and healthcare payer perspective, respectively.

CONCLUSIONS

In addition to preventing unnecessary morbidity and mortality, routine childhood immunization is cost-saving. Continued maintenance of high vaccination coverage is necessary to ensure sustained clinical and economic benefits of the vaccination program.

Impact of Routine Childhood Immunization in Reducing Vaccine-Preventable Diseases in the United States

BACKGROUND AND OBJECTIVES

Current routine immunizations for children aged ≤10 years in the United States in 2019 cover 14 vaccine-preventable diseases. We characterize the public-health impact of vaccination by providing updated estimates of disease incidence with and without universally recommended pediatric vaccines.

METHODS

Prevaccine disease incidence was obtained from published data or calculated using annual case estimates from the prevaccine period and United States population estimates during the same period. Vaccine-era incidence was calculated as the average incidence over the most recent 5 years of available surveillance data or obtained from published estimates (if surveillance data were not available). We adjusted for underreporting and calculated the percent reduction in overall and age-specific incidence for each disease. We multiplied prevaccine and vaccine-era incidence rates by 2019 United States population estimates to calculate annual number of cases averted by vaccination.

RESULTS

Routine immunization reduced the incidence of all targeted diseases, leading to reductions in incidence ranging from 17% (influenza) to 100% (diphtheria, Haemophilus influenzae type b, measles, mumps, polio, and rubella). For the 2019 United States population of 328 million people, these reductions equate to >24 million cases of vaccine-preventable disease averted. Vaccine-era disease incidence estimates remained highest for influenza (13 412 per 100 000) and Streptococcus pneumoniae-related acute otitis media (2756 per 100 000).

CONCLUSIONS

Routine childhood immunization in the United States continues to yield considerable sustained reductions in incidence across all targeted diseases. Efforts to maintain and improve vaccination coverage are necessary to continue experiencing low incidence levels of vaccine-preventable diseases.

Modeled impact of the COVID-19 pandemic and associated reduction in adult vaccinations on herpes zoster in the United States

Due to COVID-19, vaccinations dropped in 2020 and 2021. We estimated the impact of reduced recombinant zoster vaccine (RZV) use on herpes zoster (HZ) cases, complications, and quality-adjusted life-year (QALY) losses among older adults. Various scenarios were compared with Markov models using data from national sources, clinical trials, and literature. Missed series initiations were calculated based on RZV distributed doses. In 2020, 3.9 million RZV series initiations were missed, resulting in 31,945 HZ cases, 2,714 postherpetic neuralgia cases, and 610 lost QALYs. Scenarios further projected disease burden increases if individuals remain unvaccinated in 2021 or the same number of initiations are missed in 2021. Health professionals should emphasize the importance of vaccination against all preventable diseases during the COVID-19 era.

12. Modeled Impact of the COVID-19 Pandemic and Associated Reduced Adult Vaccinations on Herpes Zoster in the United States

Background

During the COVID-19 pandemic, adult vaccination in the United States (US) decreased substantially in 2020. Unlike other vaccine-preventable diseases where individuals may have experienced reduced risk due to COVID-related mitigation efforts (e.g., lockdown restrictions, use of face masks), individuals remained at risk of herpes zoster (HZ). This study projects the impact of reduced recombinant zoster vaccine (RZV) use on HZ cases and complications in the US.

Methods

A multi-cohort Markov model estimated the impact of missed RZV vaccinations, by comparing scenarios with and without missed vaccinations between Apr-Dec 2020, on cases of HZ, postherpetic neuralgia (PHN), and quality-adjusted life-years (QALYs) among US adults aged ≥ 50 years. Epidemiology, RZV efficacy, and utility inputs were obtained from standard US sources, clinical trial data, and published literature. Missed doses were estimated using data on RZV doses and an assumed 43% reduction in RZV vaccinations during the pandemic, based on publicly available data. Deterministic sensitivity and scenario analyses were conducted.

Results

In 2020, approximately 21 million (M) RZV distributed doses were expected, including an estimated 9.2M RZV series initiations in Apr-Dec. An estimated 3.9M RZV series initiations were missed, resulting in 31,945 projected HZ cases, 2,714 PHN cases, and 610 lost QALYs projected over a 1-year follow up. If individuals with missed RZV initiations remain unvaccinated in 2021, avoidable HZ cases will increase to 63,117 over 2 years. Further, if the same number of RZV initiations are missed in 2021, 95,062 avoidable HZ cases are expected. In a sensitivity analysis assuming 30% RZV reduction, 18,020 avoidable HZ cases and 1,531 PHN cases were observed over 1 year.

Conclusion

Adding to the substantial COVID-19 infection-related morbidity and mortality, reduced RZV use during the pandemic resulted in further burden from avoidable HZ cases. Health care providers should continue to emphasize the importance of vaccination against HZ and other preventable diseases during the pandemic.

Funding

GlaxoSmithKline Biologicals SA (GSK study identifier: [VEO-000222]).

Acknowledgement

Business & Decision Life Sciences c/o GSK (Coordination: Quentin Rayée).

Disclosures

Elizabeth M. La, PhD, The GSK group of companies (Employee, Shareholder) Desmond Curran, PhD, The GSK group of companies (Employee, Shareholder) Ahmed Salem, MSc, The GSK group of companies (Employee) David Singer, PharmD, MS, The GSK group of companies (Employee) Nicolas Lecrenier, Ing, PhD, The GSK group of companies (Employee, Shareholder) Sara Poston, PharmD, The GSK group of companies (Employee, Shareholder)

20. Cost-Effectiveness of Recombinant Zoster Vaccine for Vaccinating Immunocompromised Adults Against Herpes Zoster in the United States

Background

Individuals who are immunocompromised (IC) due to disease or therapy are at increased risk of herpes zoster (HZ), with HZ cases in IC populations also resulting in increased health care resource use and costs as compared with the immunocompetent population. This study assesses the cost-effectiveness of recombinant zoster vaccine (RZV) versus no vaccine for the prevention of HZ in IC adults aged ≥ 18 years in the United States (US).

Methods

A Markov model with a one-year cycle length was developed to follow a hypothetical cohort of one million IC individuals for a 30-year time horizon. The model estimates health and cost outcomes associated with RZV versus no vaccine. The base-case analysis considered hematopoietic stem cell transplant (HSCT) recipients who were assumed to remain IC for five years post-transplant. Second-dose compliance was assumed to be 100%, with efficacy and waning inputs based on clinical trial data. Epidemiological, cost, and utility inputs were obtained from standard US sources and published literature. Costs and quality-adjusted life-years (QALYs) were discounted at 3% per year. Sensitivity, threshold, and scenario analyses were conducted, including scenarios of four other IC conditions.

Results

In the modeled hypothetical cohort of one million HSCT recipients, RZV resulted in 116,790 fewer HZ cases and 21,446 fewer postherpetic neuralgia cases versus no vaccine, 5,545 fewer QALYs lost and a societal cost-savings of &5.4 million. The number needed to vaccinate to prevent one HZ case was estimated to be 9. HSCT population results were shown to be robust in sensitivity and threshold analyses. In scenario analyses, RZV was cost saving for renal transplant recipients. Incremental cost-effectiveness ratios for other IC populations were &33,268 per QALY gained for human immunodeficiency virus, &67,682 for breast cancer, and &95,972 for Hodgkin lymphoma.

Conclusion

Results suggest that RZV is a cost-effective option for vaccinating US IC adults for the prevention of HZ and associated complications.

Disclosures

Desmond Curran, PhD, The GSK group of companies (Employee, Shareholder) Ahmed Salem, MSc, The GSK group of companies (Employee) Stéphane Lorenc, NA, GSK group of companies (Consultant) Brandon Patterson, PharmD, PhD, GSK group of companies (Shareholder) Justin Carrico, BS, GSK group of companies (Consultant)RTI Health Solutions (Employee) Katherine A. Hicks, MS, BSPH, GSK group of companies (Consultant)RTI Health Solutions (Employee) Elizabeth M. La, PhD, The GSK group of companies (Employee, Shareholder) Sara Poston, PharmD, The GSK group of companies (Employee, Shareholder) Christopher F. Carpenter, MD, MHSA, GSK group of companies (Consultant)

National and State-Level Composite Completion of Recommended Vaccines Among Adolescents in the United States, 2015-2018

BACKGROUND

Routine adolescent vaccination recommendations in the United States include tetanus, diphtheria, and acellular pertussis, quadrivalent meningococcal conjugate vaccine, and human papillomavirus vaccines. Although coverage for these individual vaccines is known, limited data are available on composite completion for all three vaccines.

METHODS

This cross-sectional analysis of pooled 2015-2018 National Immunization Survey-Teen data used logistic regression to estimate model-adjusted composite vaccination completion nationally and by state among United States adolescents aged 17 years. National Immunization Survey-Teen data were combined with state-level data to estimate a multilevel model identifying factors associated with composite vaccination completion.

RESULTS

The pooled model-adjusted composite vaccination completion was 30.6% (95% confidence interval [CI], 30.13%-31.04%) nationally, varying from 11.3% in Idaho (6.91%-17.95%) to 56.4% (49.81%-62.82%) in Rhode Island. Individual-level factors with the greatest impact on composite completion were having a provider's recommendation for human papillomavirus vaccination (odds ratio, 3.24; 95% CI, 2.76-3.80) and a check-up visit at age 16-17 years (odds ratio, 2.35; 95% CI, 1.80-3.07), with other individual-level factors associated with completion including being Medicaid insured, female, Hispanic, or non-Hispanic black. State-level quadrivalent meningococcal conjugate vaccination mandates were also associated with an increased likelihood of composite vaccination completion (odds ratio, 1.64; 95% CI, 1.16-2.33).

CONCLUSIONS

Fewer than one-third of 17-year-old individuals have completed all three recommended vaccines, with rates varying by state. Although this study identified implementable strategies to improve composite completion, additional research is needed to further understand factors associated with adolescent vaccination completion.

State-Level Variations and Factors Associated with Adult Vaccination Coverage: A Multilevel Modeling Approach

BACKGROUND

Adult vaccination rates in the USA are generally low and fall short of public health goals.

OBJECTIVES

Our aim was to evaluate the effect of state-level characteristics on adult vaccination coverage in the USA.

METHODS

This study was a cross-sectional, retrospective analysis of 2015-2017 Behavioral Risk Factor Surveillance System data, conducted from March to October 2019 and including seasonal influenza; pneumococcal; tetanus, diphtheria, and acellular pertussis (Tdap); and herpes zoster (HZ) vaccines. Multilevel logistic regression models examined interstate vaccination coverage variability and assessed the impact of state-level characteristics, with model-adjusted coverage estimated.

RESULTS

Model-adjusted vaccination coverage varied by state, with 35.1-48.1% coverage for influenza (2017), 68.2-80.8% for pneumococcal (2017), 21.9-46.5% for Tdap (2016), and 30.5-50.9% for HZ (2017). Characteristics associated with vaccination included state-level insurance coverage, pharmacists' vaccination authority, vaccination exemptions, and adult immunization information systems participation, as well as individual-level measures of income and education. After adjusting for these factors, substantial interstate heterogeneity remained.

CONCLUSIONS

Model-adjusted coverage was generally low and varied by state. A small number of state-level characteristics partially explained interstate coverage variability. This and future research assessing additional state characteristics may help determine policies most likely to increase adult vaccination.

Meningococcal B vaccination coverage among older adolescents in the United States

BACKGROUND

Serogroup B meningococcal (MenB) vaccination recommendations for adolescents in the United States (US) include routine vaccination for all individuals at increased risk and vaccination for individuals not at increased risk aged 16-23 years (preferred age 16-18 years) based on shared clinical decision-making. The two licensed MenB vaccines require administration of ≥2 doses.

METHODS

This cross-sectional study analyzed 2017-2018 National Immunization Survey-Teen (NIS-Teen) data to evaluate ≥1 dose and ≥2 dose MenB vaccination coverage among adolescents aged 17 years. Multivariable logistic regression was used to further evaluate determinants of MenB vaccination.

RESULTS

Nationally, MenB vaccination coverage among 17-year-olds increased from 14.5% in 2017 to 17.2% in 2018 for ≥1 dose and from 6.3% to 8.4% for ≥2 doses. MenB vaccination coverage (2017-2018) was the lowest in the South (≥1 dose: 14.6%; ≥2 doses: 6.3%) and highest in the Northeast region (18.3% and 9.3%), with variation observed by census division. Adolescents were more likely to have received ≥1 dose of MenB vaccine if they had any Medicaid insurance (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.32-2.39) or had received human papillomavirus (OR, 1.94; 95% CI, 1.41-2.67) or meningococcal A, C, W, and Y (OR, 4.03; 95% CI, 2.92-5.56) vaccinations.

CONCLUSIONS

MenB first-dose coverage in the US is low, and even lower for a second dose, with regional variation. Being up to date with other routinely administered vaccines increased the likelihood of receiving MenB vaccination.

The Cost-Effectiveness and Budget Impact of Ibalizumab-uiyk for Adults with Multidrug-Resistant HIV-1 Infection in the United States

BACKGROUND

Ibalizumab-uiyk (ibalizumab) is a first-in-class, long-acting, postattachment HIV-1 inhibitor for adults with multidrug-resistant (MDR) HIV-1 infection. This analysis examines the cost-effectiveness and budget impact of ibalizumab treatment for this difficult-to-treat population in the United States.

METHODS

A Markov model followed cohorts of adults with MDR HIV-1 infection through two final lines of antiretroviral therapy: ibalizumab + optimized background therapy (OBT) or OBT alone followed by nonsuppressive therapy. Model inputs were based on ibalizumab clinical trial data, market uptake projections, and published literature, with costs in 2019 dollars. The cost-effectiveness analysis assessed costs and health outcomes from a health care sector perspective for individuals receiving ibalizumab + OBT versus OBT alone over a lifetime time horizon. The budget-impact analysis estimated the impact on payer budgets of the introduction of ibalizumab over 3 years for a hypothetical commercial health plan.

RESULTS

Compared with individuals receiving OBT alone, individuals receiving ibalizumab + OBT incurred higher costs but lived longer, healthier lives, with an incremental cost of $133,040 per QALY gained. For a hypothetical commercial health plan with 1 million members, the introduction of ibalizumab + OBT was estimated to increase budgets by $217,260, $385,245, and $560,310 ($0.018, $0.032, and $0.047 per member per month) in years 1, 2, and 3, respectively. These results were found to be robust in sensitivity and scenario analyses.

CONCLUSIONS

Ibalizumab may represent a cost-effective and affordable option to improve health outcomes for individuals with MDR HIV-1 infection.

87. Impact of State of Residence on Adult Vaccination Uptake: A Multilevel Modeling Approach

Background

Previous studies on adult vaccination coverage found inter-state variability that persists after adjusting for individual demographic factors. Assessing the impact of state-level factors may help improve uptake strategies. This study aimed to:

• Update previous estimates of state-level, model-adjusted coverage rates for influenza; pneumococcal; tetanus, diphtheria, and acellular pertussis (Tdap); and herpes zoster (HZ) vaccines (individually and in compliance with all age-appropriate recommended vaccinations)

• Evaluate effects of individual and state-level factors on adult vaccination coverage using a multilevel modeling framework.

Methods

Behavioral Risk Factor Surveillance System (BRFSS) survey data (2015–2017) were retrospectively analyzed. Multivariable logistic regression models estimated state vaccination coverage and compliance using predicted marginal proportions. BRFSS data were then combined with external state-level data to estimate multilevel models evaluating effects of state-level factors on coverage. Weighted odds ratios and measures of cluster variation were estimated.

Results

Adult vaccination coverage and compliance varied by state, even after adjusting for individual characteristics, with coverage ranging as follows:

• Influenza (2017): 35.1–48.1%

• Pneumococcal (2017): 68.2–80.8%

• Tdap (2016): 21.9–46.5%

• HZ (2017): 30.5–50.9%

Few state-level variables were retained in final multilevel models, and measures of cluster variation suggested substantial residual variation unexplained by individual and state-level variables. Key state-level variables positively associated with vaccination included health insurance coverage rates (influenza/HZ), pharmacists’ vaccination authority (HZ), presence of childhood vaccination exemptions (pneumococcal/Tdap), and adult immunization information system participation (Tdap/HZ).

Conclusion

Adult vaccination coverage and compliance continue to show substantial variation by state even after adjusting for individual and state-level characteristics associated with vaccination. Further research is needed to assess additional state or local factors impacting vaccination disparities.

Funding

GlaxoSmithKline Biologicals SA (study identifier: HO-18-19794)

Disclosures

Shannon Hunter, MS, GSK (Other Financial or Material Support, Ms. Hunter is an employee of RTI Health Solutions, who received consultancy fees from GSK for conduct of the study. Ms. Hunter received no direct compensation from the Sponsor.) Diana Garbinsky, MS, GSK (Other Financial or Material Support, The study was conducted by RTI Health Solutions, which received consultancy fees from GSK. I am a salaried employee at RTI Health Solutions and received no direct compensation from GSK for the conduct of this study..) Elizabeth M. La, PhD, RTI Health Solutions (Employee) Sara Poston, PharmD, The GlaxoSmithKline group of companies (Employee, Shareholder) Cosmina Hogea, PhD, GlaxoSmithKline (Employee, Shareholder)

1386. Current Estimates of the Impact of Routine Childhood Immunizations in Reducing Vaccine-Preventable Diseases in the United States

Background

Routine immunizations for children aged 10 years and younger in the United States (US) currently cover 14 diseases. Updated estimates of public health impact are needed, given changes in disease epidemiology, evolving recommendations, and the dynamic nature of compliance with the immunization schedule.

Methods

Pre-vaccine disease incidence was estimated before each routine vaccine was recommended, with average values across multiple years obtained directly from published literature or calculated based on disease surveillance data or annual case estimates from the published literature. Pre-vaccine incidence then was compared to current, post-vaccine incidence, which was generally calculated as average values over the most recent 5 years of available incidence data. Overall incidence estimates and estimates by age group were calculated. Differences in pre- and post-vaccine disease incidence rates were used to calculate the annual number of cases averted, based on 2019 US population estimates. This analysis did not separately estimate the proportion of disease incidence reduction that may be attributed to adult vaccines or booster doses.

Results

Post-vaccine disease incidence decreased overall and for all age groups across all diseases evaluated (Table 1). Decreases ranged from 17.4% for influenza to 100.0% for polio (Figure 1). Over 90% reduction in incidence was achieved for 10 of the 14 diseases evaluated (including reduction in incidence of rotavirus hospitalizations). Overall post-vaccine disease incidence estimates were highest for influenza, rotavirus, and varicella. Estimated annual cases averted by vaccination in 2019 ranged from 1,269 for tetanus to more than 4.2 million for varicella.

Table 1. Pre- and Post-Vaccine Disease Incidence Estimates, Annual Cases, and 2019 Cases Averted, by Disease

Figure 1. Percentage Reduction in Disease Incidence Post-Vaccine, by Disease

Conclusion

Routine childhood immunization in the US continues to result in high, sustained reduction in disease across all vaccines and for all age groups evaluated.

Disclosures

Elizabeth M. La, PhD, RTI Health Solutions (Employee) Justin Carrico, BS, GlaxoSmithKline (Consultant) Sandra E. Talbird, MSPH, RTI Health Solutions (Employee) Ya-Ting Chen, PhD, Merck & Co., Inc. (Employee, Shareholder) Mawuli K. Nyaku, DrPh, Merck & Co. Inc. (Employee, Shareholder) Cristina Carias, PhD, Merck (Employee, Shareholder) Gary S. Marshall, MD, GlaxoSmithKline (Consultant, Scientific Research Study Investigator)Merck (Consultant, Scientific Research Study Investigator)Pfizer (Consultant, Scientific Research Study Investigator)Sanofi Pasteur (Consultant, Grant/Research Support, Scientific Research Study Investigator, Honorarium for conference lecture)Seqirus (Consultant, Scientific Research Study Investigator) Craig S. Roberts, PharmD, MPA, MBA, Merck & Co., Inc (Employee, Shareholder)

179. Individual and State-level Factors Associated with Receipt of Multiple Recommended Adolescent Vaccines in the United States

Background

The Advisory Committee on Immunization Practices (ACIP) routinely recommends several adolescent vaccines, including human papillomavirus (HPV); quadrivalent meningococcal conjugate (MenACWY); and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines. Limited data are available on the percentage of adolescents receiving this complement of ACIP-recommended vaccines and factors that may increase likelihood of completion.

Methods

This study used 2015–18 pooled National Immunization Survey-Teen (NIS-Teen) data to estimate national and state-level completion rates by age 17 of a two-dose MenACWY series, two- or three- dose HPV series (depending on age at first vaccination), and a Tdap vaccine, using multivariable logistic regression modeling to adjust for individual characteristics. NIS-Teen data were then combined with public state-level data to construct a multilevel model evaluating effects of both individual- and state-level factors on completion.

Results

After adjusting for individual-level factors, the national completion rate for these ACIP-recommended vaccines by age 17 was 30.6% (95% confidence interval [CI]: 30.1–31.0%). However, rates for individual states varied substantially, from 11.3% in Idaho (CI: 6.9–18.0%) to 56.4% in Rhode Island (CI: 49.8–62.8%) (Figure 1).

In the multilevel model, individual characteristics associated with increased likelihood of receiving the recommended vaccines by age 17 included female gender, black or Hispanic race, Medicaid coverage (vs. private/other), last provider visit at age 16 or 17, generally having ≥1 provider visit in last year, and receiving a provider recommendation for HPV vaccination. Residing in a state with a MenACWY vaccination mandate for elementary and secondary schools was the only state-level variable that significantly increased the likelihood of completion (odds ratio: 1.6; CI: 1.2–2.3) (Figure 2).

Figure 1: Model-Adjusted Completion Rates of ACIP-Recommended HPV, MenACWY, and Tdap Vaccines by Age 17 Years in the United States, 2015–18. ACIP, Advisory Committee on Immunization Practices; HPV, human papillomavirus; MenACWY, quadrivalent meningococcal conjugate; Tdap, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis. Note: Vaccination completion is based on completion of the HPV series (i.e., receipt of 2 doses for individuals aged 9–14 years at first vaccination or receipt of 3 doses for individuals aged 15 years or older at first vaccination), completion of the MenACWY series (i.e., receipt of 2 doses), and receipt of a Tdap vaccine. Note: Model-adjusted composite vaccination completion is adjusted for sex, race/ethnicity, mother’s educational attainment, health insurance status, continuity of health insurance coverage since age 11, whether the individual was 16 or 17 years old at their last checkup, number of physician or other healthcare professional visits in past 12 months, whether a doctor or other healthcare professional ever recommended that the individual receive HPV vaccination, and state. The model-adjusted estimate is generated by taking the average of the predicted probability of vaccination for each individual as if they were all from the same state (while retaining all other characteristics).

Figure 2: Individual-Level and State-Level Characteristics Associated with an Individual’s Completion of ACIP-Recommended HPV, MenACWY, and Tdap Vaccines by Age 17 Years in the United States, 2015–18. ACIP, Advisory Committee on Immunization Practices; CI, confidence interval; HCP, healthcare professional; HPV, human papillomavirus; MenACWY, quadrivalent meningococcal conjugate; ref, referent category; Tdap, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis. Note: Bold characters and darker circles indicate significant results. Note: Vaccination completion is based on completion of the HPV series (i.e., receipt of 2 doses for individuals aged 9–14 years at first vaccination or receipt of 3 doses for individuals aged 15 years or older at first vaccination), completion of the MenACWY series (i.e., receipt of 2 doses), and receipt of a Tdap vaccine.

Conclusion

Recommended adolescent vaccine completion rates are suboptimal and highly variable across states. Provider recommendations, visits at 16–17 years of age, and state mandates for MenACWY are implementable strategies associated with completion of recommended adolescent vaccines.

Funding

GlaxoSmithKline Biologicals SA (study identifier: HO-19-19991)

Disclosures

Elizabeth M. La, PhD, RTI Health Solutions (Employee) Diana Garbinsky, MS, GSK (Other Financial or Material Support, The study was conducted by RTI Health Solutions, which received consultancy fees from GSK. I am a salaried employee at RTI Health Solutions and received no direct compensation from GSK for the conduct of this study..) Shannon Hunter, MS, GSK (Other Financial or Material Support, Ms. Hunter is an employee of RTI Health Solutions, who received consultancy fees from GSK for conduct of the study. Ms. Hunter received no direct compensation from the Sponsor.) Sara Poston, PharmD, The GlaxoSmithKline group of companies (Employee, Shareholder) Patricia Novy, PhD, GSK (Employee, Shareholder) Parinaz Ghaswalla, PhD, ORCID: 0000-0002-2883-5590, GlaxoSmithKline (Employee, Shareholder)

Impact of population aging on the burden of vaccine-preventable diseases among older adults in the United States

Despite vaccination recommendations, the burden of vaccine-preventable diseases remains high in older adults in the United States (US), contributing to substantial morbidity, mortality, and health care resource use and costs. To adequately plan for health care resource needs and to help inform vaccination policies, burden of disease projections that account for population aging over the coming decades are needed. As a first step, this exploratory study projects the burden of influenza, pertussis, herpes zoster, and pneumococcal disease in adults aged 50 y and older in the US, using a population-based modeling framework with separate decision trees for each vaccine-preventable disease. The model uses projected population estimates from the US Census Bureau to account for changes in the US population over time and then calculates expected numbers of cases and associated costs for each disease, keeping current estimates of age-specific disease incidence, vaccine coverage, and efficacy constant over time. This approach was used to focus the exploratory analysis on the burden of disease that may be expected due to population changes alone, assuming that all else remains unchanged. Due to population growth and the shifting age distribution over the next 30 y, the annual societal economic burden for the four vaccine-preventable diseases is projected to increase from approximately $35 billion to $49 billion, resulting in cumulative costs of approximately $1.3 trillion, as well as more than 1 million disease-related deaths. Given such notable burden, further efforts to increase vaccination coverage and effectiveness in older adults are needed.

Cost calculator for mass vaccination response to a US college campus outbreak of serogroup B meningococcal disease

Serogroup B (MenB) is the leading cause of meningococcal disease among 16- to 23-year-olds in the United States and has been responsible for all 10 college outbreaks between 2011 and 2017. Outbreak-associated costs levy a substantial and unforeseen burden on colleges/universities and surrounding communities, in part because they involve collaboration with local and state health departments to develop points-of-dispensing (PODs) outbreak response plans and rapid mass vaccination of a large at-risk student population. The MenB outbreak at Providence College in 2015 was used as a case study to develop an Excel-based Meningococcal Outbreak Cost Calculator that uses target populations for mass vaccination to estimate the costs and resources associated with a meningococcal disease outbreak response. Resources include labor, medical supply, and other nonlabor costs (eg, vaccine-related adverse event costs) over an 18-month period following the outbreak declaration. Based on the actual Providence College population partially or fully vaccinated with MenB-FHbp (Trumenba®, Bivalent rLP2086) (3-dose schedule), the calculator estimated aggregate direct costs of $1,350,963 over 18 months post-outbreak for 4,418 individuals. For planned full vaccination of the enrolled undergraduate population (4,795 individuals), the tool estimated total costs of $1,798,399. In both cases, the majority of costs were for medical supplies (88%-89%) and contract services (7%-9%). This calculator can help to plan a mass vaccination campaign for MenB outbreak control, and underscores the need to vaccinate pre-emptively against diverse disease-causing strains before an outbreak occurs.

683. Cost Calculator for Mass Vaccination Response to a US College Campus Outbreak of Serogroup B Meningococcal Disease

Background

US college students are at increased risk for serogroup B meningococcal disease (MenB). MenB caused ~57% of meningococcal disease cases among 16- to 23-year-olds in 2016, and was responsible for 10 US college outbreaks from 2011−2017 involving 41 cases and an at-risk population of ~182,000 enrolled undergraduates. Outbreaks cause disruptive anxiety among university communities and implementing a mass vaccination response imposes an often unforeseen financial burden. This study aimed to enumerate costs incurred during a points-of-dispensing, mass vaccination response to a US campus MenB outbreak.

Methods

The 2015 MenB outbreak at Providence College was used as a case study to develop an Excel-based (Microsoft, Redmond, WA) cost calculator to capture costs and resources associated with a MenB outbreak response. The calculator has user-modifiable inputs related to the vaccine-eligible population, accounts for each vaccination event and vaccine dose (Figure 1), and estimates direct costs (2016 USD) during 18 months post-outbreak. Potential/expected costs computed (assuming 100% vaccine coverage) were compared with estimated actual costs incurred during the outbreak, using a micro-costing approach.

Results

The estimated total cost for full vaccination of 4,795 eligible individuals was $1,798,399 ($375.06/person); based on actual vaccinations received, the cost calculator computed $1,350,963 in aggregate direct costs ($636.05/person fully vaccinated) (Table 1). In both analyses, medical supplies were the majority of costs (88–89%), followed by labor resources (7–9%).

Conclusion

This cost calculator quantifies the direct cost of a mass vaccination response to one campus MenB outbreak. Although the cost estimates herein are higher than previously reported, the calculator does not account for follow-up costs or productivity losses and therefore underestimates the true economic burden of a campus MenB outbreak. This outbreak response cost calculator can be used to aid in response planning and highlights the need to shift the public health response from outbreak control to prevention by proactive, pre-emptive vaccination using available licensed meningococcal vaccines.

Disclosures

E. M. La, RTI Health Solutions (RTI-HS): Employee and RTI-HS is an independent scientific research organization which was retained pursuant to a contract with Pfizer to conduct the research services which are the subject of this presentation/abstract., Salary and The RTI-HS employees who worked on this project did not receive compensation from Pfizer or any other organization, other than RTI-HS salaries.. S. E. Talbird, RTI Health Solutions (RTI-HS): Employee and RTI-HS is an independent scientific research organization which was retained pursuant to a contract with Pfizer to conduct the research services which are the subject of this presentation/abstract., Salary and The RTI-HS employees who worked on this project did not receive compensation from Pfizer or any other organization, other than RTI-HS salaries.. J. Fain, Pfizer Inc.: Employee at time of Study and Employee, Salary. L. Huang, Pfizer: Employee and Shareholder, Salary and Stocks. A. Srivastava, Pfizer: Employee and Shareholder, Salary and Stocks.

Understanding the role of exogenous boosting in modeling varicella vaccination

INTRODUCTION

The exogenous boosting (EB) hypothesis posits that cell-mediated immunity is boosted for individuals reexposed to varicella-zoster virus (VZV). Historically, mathematical models of the impact of universal childhood varicella vaccination (UVV) have used limited data to capture EB and often conclude that UVV will temporarily increase herpes zoster (HZ) incidence.

AREAS COVERED

We updated a 2013 systematic literature review of 40 studies to summarize new evidence from observational or modeling studies related to EB and its parameterization. We abstracted data on observational study designs and mathematical model structures, EB frameworks, and HZ-related parameter values.

EXPERT COMMENTARY

This review identified an additional 41 studies: 22 observational and 19 modeling studies. Observational analyses generally reported pre-UVV increases in HZ incidence, making it difficult to attribute post-UVV increases to UVV versus other causes. Modeling studies considered a range of EB frameworks, from no boosting to full permanent immunity. Mathematical modeling efforts are needed in countries with long-standing vaccination programs to capture the dynamics of VZV transmission and temporal changes that may affect HZ incidence. Use of real-world pre-/postvaccination data on varicella and HZ incidence to validate model predictions may improve approaches to EB parameterization and understanding of the effects of varicella vaccination programs.

Treatment patterns and health care resource use in patients receiving multiple lines of therapy for metastatic squamous cell carcinoma of the head and neck in the United Kingdom

This study evaluated the patterns of care and health care resource use (HCRU) in patients with metastatic squamous cell carcinoma of the head and neck (SCCHN) who received ≥3 lines of systemic therapy in the United Kingdom (UK). Oncologists (n = 40) abstracted medical records for patients with metastatic SCCHN who initiated third‐line systemic therapy during 1 January 2011–30 August 2014 (n = 220). Patient characteristics, treatment patterns and SCCHN‐related HCRU were summarised descriptively for the metastatic period; exploratory multivariable regression analyses were conducted on select HCRU outcomes. At metastatic diagnosis, most patients had an Eastern Cooperative Oncology Group performance status (PS) of 0/1 (95%). For patients with PS 0/1, the most common first‐line treatment was cisplatin+5‐fluorouracil (5‐FU); docetaxel was the most common second‐ and third‐line treatment. For patients with PS ≥ 2, the most common first‐, second‐, and third‐line treatments were carboplatin+5‐FU, cetuximab, and methotrexate, respectively. Most patients received supportive care during (85%) and after (89%) therapy. This study provides useful information, prior to the availability of immunotherapy, on patient characteristics, treatment patterns, HCRU, and survival in a real‐world UK population with metastatic SCCHN receiving ≥3 lines of systemic therapy. Patterns of care and HCRU varied among patients with metastatic SCCHN; specific systemic therapies varied by patient PS.

An analysis of factors associated with influenza, pneumoccocal, Tdap, and herpes zoster vaccine uptake in the US adult population and corresponding inter-state variability

Despite longstanding recommendations for routine vaccination against influenza; pneumococcal; tetanus, diphtheria, acellular pertussis (Tdap); and herpes zoster (HZ) among the United States general adult population, vaccine uptake remains low. Understanding factors that influence adult vaccination and coverage variability beyond the national level are important steps toward developing targeted strategies for increasing vaccination coverage. A retrospective analysis was conducted using data from the Behavioral Risk Factor Surveillance System (2011–2014). Multivariable logistic regression modeling was employed to identify individual factors associated with vaccination (socio-demographics, health status, healthcare utilization, state of residence) and generate adjusted vaccination coverage and compliance estimates nationally and by state. Results indicated that multiple characteristics were consistently associated with a higher likelihood of vaccination across all four vaccines, including female sex, increased educational attainment, and annual household income. Model-adjusted vaccination coverage estimates varied widely by state, with inter-state variability for the most recent year of data as follows: influenza (aged ≥18 years) 30.2–49.5%; pneumococcal (aged ≥65 years) 64.0–74.7%; Tdap (aged ≥18 years) 18.7–46.6%; and HZ (aged ≥60 years) 21.3–42.9%. Model-adjusted compliance with age-appropriate recommendations across vaccines was low and also varied by state: influenza+Tdap (aged 18–59 years) 7.9–24.7%; influenza+Tdap+HZ (aged 60–64 years) 4.1–14.4%; and influenza+Tdap+HZ+pneumococcal (aged ≥65 years) 3.0–18.3%. In summary, after adjusting for individual characteristics associated with vaccination, substantial heterogeneity across states remained, suggesting that other local factors (e.g. state policies) may be impacting adult vaccines uptake. Further research is needed to understand such factors, focusing on differences between states with high versus low vaccination coverage.

Impact of State Psychiatric Hospital Waitlists on Monthly Admissions

OBJECTIVE

This study estimated the effects of a waitlist policy on the monthly number and case mix of admissions to state psychiatric hospitals (SPHs) in North Carolina (NC).

METHODS

Descriptive analyses compared pre/postwaitlist differences in the monthly number and case mix of nonforensic adult admissions (N=72,035) to NC's four SPHs by using data from the three years before and the three years after the waitlist announcement. Hospital-level fixed-effects regression models further evaluated the waitlist policy's impact on the number and case mix of admissions.

RESULTS

Regression results confirmed that the waitlist policy was associated with both fewer admissions and changes to the case mix of admissions, including a 4.2% decrease in the percentage of monthly admissions by patients with diagnoses of substance abuse disorders (p=.002) across all months postwaitlist (partially offset by an increase of patients with diagnoses of severe mental illness alone).

CONCLUSIONS

Waitlists led to reduced monthly admissions and altered case mix following implementation at NC SPHs.

Increasing Access to State Psychiatric Hospital Beds: Exploring Supply-Side Solutions

OBJECTIVE

The objective of this study was to identify supply-side interventions to reduce state psychiatric hospital admission delays.

METHODS

Healthcare Enterprise Accounts Receivable Tracking System (HEARTS) data were collected for all patients admitted between July 1, 2010, and July 31, 2012, to one of North Carolina's three state-operated psychiatric hospitals (N=3,156). Additional information on hospital use was collected at nine meetings with hospital administrators and other local stakeholders. A discrete-event simulation model was built to simulate the flow of adult nonforensic patients through the hospital. Hypothetical scenarios were used to evaluate the effects of varying levels of increased capacity on annual number of admissions and average patient wait time prior to admission.

RESULTS

In the base case, the model closely approximated actual state hospital utilization, with an average of 1,251±65 annual admissions and a preadmission wait time of 3.3±.1 days across 50 simulations. Results from simulated expansion scenarios highlighted substantial capacity shortfalls in the current system. For example, opening an additional 24-bed unit was projected to decrease average wait time by only 6%. Capacity would need to be increased by 165% (356 beds) to reduce average wait time below 24 hours.

CONCLUSIONS

Without more robust community-based hospital and residential capacity, major increases in state psychiatric hospital inpatient capacity are necessary to ensure timely admission of people in crisis.

Cost-effectiveness analysis of tenofovir/emtricitabine and abacavir/lamivudine in combination with efavirenz or atazanavir/ritonavir for treatment-naïve adults with HIV-1 infection in the UK, based on the AIDS Clinical Trials Group 5202 clinical trial

OBJECTIVES

The aim of the study was to assess the cost-effectiveness of the four regimens studied in the AIDS Clinical Trials Group (ACTG) 5202 clinical trial, tenofovir/emtricitabine (TDF/FTC) or abacavir/lamivudine (ABC/3TC) in combination with efavirenz (EFV) or atazanavir/ritonavir (ATV/r), for treatment-naïve adults with HIV-1 infection in the UK.

METHODS

A Markov model with six health states based on CD4 cell count ranges was developed to predict long-term costs and health outcomes for individuals on first-line therapy. Head-to-head efficacy data comparing TDF/FTC + EFV, TDF/FTC + ATV/r, ABC/3TC + EFV, and ABC/3TC + ATV/r were obtained from ACTG 5202 for up to 192 weeks. Antiretroviral drug costs were based on current list prices. Other medical costs (2013 UK pounds sterling), utility values, and mortality rates were obtained from published sources. Base-case, sensitivity, and subgroup analyses (by baseline viral load) were conducted.

RESULTS

Individuals using TDF/FTC-based regimens were predicted to remain on first-line therapy longer and accrue more quality-adjusted life-years (QALYs) than individuals using ABC/3TC-based regimens. At a willingness-to-pay threshold of £30 000 per QALY gained, TDF/FTC-based regimens were predicted to be cost-effective compared with ABC/3TC-based regimens, with incremental cost-effectiveness ratios of £23 355 for TDF/FTC + EFV vs. ABC/3TC + EFV and £23 785 for TDF/FTC + ATV/r vs. ABC/3TC + ATV/r. Results were generally robust in subgroup, sensitivity, and scenario analyses.

CONCLUSIONS

In an analysis of the regimens studied in ACTG 5202 for treatment-naïve adults with HIV-1 infection in the UK, TDF/FTC-based regimens yielded more favourable health outcomes and were generally predicted to be cost-effective compared with ABC/3TC-based regimens. These results confirm that TDF/FTC-based regimens are not only clinically effective but also cost-effective.