Preferences for Sexually Transmitted Infection and Cancer Vaccines in the United States and in China.

OBJECTIVES: This study assessed preferences for hypothetical vaccines for children in 2 large vaccine markets according to how the vaccine-preventable disease is transmitted via a discrete choice experiment. METHODS: Surveys in China (N = 1350) and the United States (N = 1413) were conducted from April to May 2021. The discrete choice experiment included attributes of cost, age at vaccination, transmission mode of the vaccine-preventable disease, and whether the vaccine prevents cancer. Preference utilities were modeled in a Bayesian, multinomial logistic regression model, and respondents were grouped by vaccine preference classification through a latent class analysis. RESULTS: Individuals favored vaccines against diseases with transmission modes other than sexual transmission (vaccine for sexually transmitted infection [STI] vs airborne disease, in the United States, odds ratio 0.71; 95% credible interval 0.64-0.78; in China, odds ratio 0.76; 95% credible interval 0.69-0.84). The latent class analysis revealed 6 classes: vaccine rejecters (19% in the United States and 8% in China), careful deciders (18% and 17%), preferring cancer vaccination (20% and 19%), preferring vaccinating children at older ages (10% and 11%), preferring vaccinating older ages, but indifferent about cancer vaccines (23% and 25%), and preferring vaccinating children at younger ages (10% and 19%). Vaccine rejection was higher with age in the United States versus more vaccine rejection among those at the age of 18 to 24 and ≥ 64 years in China. CONCLUSION: The public had strong preferences against giving their child an STI vaccine, and the class preferring a cancer vaccine was less accepting of an STI vaccine. Overall, this study points to the need for more education about how some STI vaccines could also prevent cancers.

Declines in Pneumonia Mortality Following the Introduction of Pneumococcal Conjugate Vaccines in Latin American and Caribbean Countries.

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) are recommended for use in pediatric immunization programs worldwide. Few data are available on their effect against mortality. We present a multicountry evaluation of the population-level impact of PCVs against death due to pneumonia in children < 5 years of age. METHODS: We obtained national-level mortality data between 2000 and 2016 from 10 Latin American and Caribbean countries, using the standardized protocol. Time series models were used to evaluate the decline in all-cause pneumonia deaths during the postvaccination period while controlling for unrelated temporal trends using control causes of death. RESULTS: The estimated declines in pneumonia mortality following the introduction of PCVs ranged from 11% to 35% among children aged 2-59 months in 5 countries: Colombia (24% [95% credible interval {CrI}, 3%-35%]), Ecuador (25% [95% CrI, 4%-41%]), Mexico (11% [95% CrI, 3%-18%]), Nicaragua (19% [95% CrI, 0-34%]), and Peru (35% [95% CrI, 20%-47%]). In Argentina, Brazil, and the Dominican Republic, the declines were not detected in the aggregated age group but were detected in certain age strata. In Guyana and Honduras, the estimates had large uncertainty, and no declines were detected. Across the 10 countries, most of which have low to moderate incidence of pneumonia mortality, PCVs have prevented nearly 4500 all-cause pneumonia deaths in children 2-59 months since introduction. CONCLUSIONS: Although the data quality was variable between countries, and the patterns varied across countries and age groups, the balance of evidence suggests that mortality due to all-cause pneumonia in children declined after PCV introduction. The impact could be greater in populations with a higher prevaccine burden of pneumonia.

A Cost-Effectiveness Analysis of Population-Level Dental Caries Prevention Strategies in US Children.

OBJECTIVE: To improve oral health disparities and outcomes among US children impacted by dental caries, there is a need to understand the cost-effectiveness of a targeted, risk-based versus universal-based approach for caries prevention. METHODS: Health and economic outcomes were simulated in a cohort of 50,000 US children aged 1-18 years, comparing current practice (CP) to risk-based-prevention (RBP) and prevention-for-all (PFA) strategies using health care sector and limited societal perspectives. Prevention included biannual oral health exams and fluoride varnish application, and one-time dental sealant placement. The primary outcome is the cost-effectiveness ratio (ICER), defined as the additional cost per quality-adjusted life year (QALY) gained when comparing each strategy to the next least costly one. RESULTS: For RBP compared to CP, the ICER was US$83,000/QALY from the health care sector perspective; for PFA compared to RBP the ICER was US$154,000/QALY. Using a limited societal perspective that includes caregiver time spent attending dental or medical setting visits, RBP compared to CP yielded a ratio of $119,000/QALY and PFA compared to RBP was $235,000/QALY. Results were most sensitive to changes in the probability of pain from an episode of dental caries, costs for prevention and restoration, and the loss in health-related quality of life due to dental caries pain. Scenario analyses evaluating a reduced intensity of prevention services yielded lower ICERs. CONCLUSION: Using a risk-based approach that identifies and targets children at increased risk for dental caries to guide the delivery of prevention services represents an economic value similar to other pediatric prevention programs.

The effectiveness of COVID-19 vaccines in Latin America, 2021: a multicenter regional case-control study.

Background: As of September 2022, nearly 1.3 billion doses of COVID-19 vaccine products have been administered in Latin America and the Caribbean, where 27% of global COVID-19 deaths have occurred. This study aimed to estimate the effectiveness of COVID-19 vaccines against lab-confirmed COVID-19 related hospitalizations and deaths among adults in Argentina, Brazil, Chile, and Colombia. Methods: Using a test-negative case control design, we evaluated the effectiveness of a primary vaccination series considering six COVID-19 vaccine products (Sputnik V, mRNA-1273, CoronaVac, ChAdOx1, BNT162b2, Ad26.COV2.S) against lab-confirmed COVID-19 hospitalizations and deaths among 83,708 hospitalized adults from February-December, 2021. Data from hospitalization records, COVID surveillance, and vaccination registries were used. Vaccine effectiveness was estimated using logistic regression ((1-OR) x 100). Findings: The average age of participants was 56.7 (SD = 17.5), and 45,894 (54.8%) were male. Adjusted VE (aVE) estimates for full vaccination against hospitalization were 82% for mRNA-1273 (95% confidence interval (CI) = -30 to 98%), 76% (71%-81%) for BNT162b2, 65% (61-68%) for ChAdOx1, 57% (10-79%) for Sputnik V, 53% (50-56%) for CoronaVac, and 46% (23-62%) for Ad26.COV2.S. Estimates, particularly for CoronaVac, varied by variant. Decreasing aVE was estimated as age increased, particularly for CoronaVac and ChAdOx1. aVE estimates against death were generally higher, with 100% (CI not estimated) for mRNA-1273, 82% (69-90%) for BNT162b2, 73% (69-77%) for ChAdOx1, 65% (60-67%) for CoronaVac, 38% (-75 to 78%) for Sputnik V, 6% (-58 to 44%) for Ad26.COV2.S. Interpretation: Primary series vaccination with available COVID-19 vaccine products was effective against COVID-19 hospitalization and mortality. Effectiveness varied by product and declined with increasing age. Funding: This study was funded by the Pan-American Health Organization (PAHO, World Health Organization (WHO)). PAHO convened and led the study implementation.

HPV vaccine introduction in the Americas: a decade of progress and lessons learned.

INTRODUCTION: Human papillomavirus (HPV) is an important public health concern due to its causative role in many cancers, especially cervical cancer, and other conditions that lead to serious health consequences in both men and women. In Latin America and the Caribbean, nearly 60,000 new cases of cervical cancer and another 7,000 HPV-associated cancers are diagnosed annually. AREAS COVERED: HPV vaccination combined with comprehensive cervical cancer control programmingis paving the way for eliminating cervical cancer as a major public health problem and drastically reducing other HPV-associated diseases. To date, 44 countries and territories in the Americas have introduced HPV vaccines as part of their national immunization programs and cervical cancer control strategies. Early lessons from HPV vaccine introduction suggest that transparent and credible evidence-based decision-making, information, education and communication about HPV and cervical cancer, coordination with existing cervical cancer control initiatives, and precise planning for ensuring effective uptake of the vaccine in target groups are all critical elements of success. EXPERT OPINION: There is an urgent need for strategies to increase HPV vaccine coverage, and as the integrated control programs evolve and other HPV-associated disease becomes important for public health, there will be a need for continued program and policy evaluation.

Projected risks and health benefits of vaccination against herpes zoster and related complications in US adults.

The Advisory Committee on Immunization Practices (ACIP) recommends recombinant zoster vaccine (RZV) to prevent against herpes zoster (HZ) and related complications in immunocompetent adults ≥50 y and immunocompromised adults ≥19 y. In 2019, a statistical safety signal for Guillain-Barré syndrome (GBS) following RZV was identified using data from the Vaccine Safety Datalink (VSD). Subsequently, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and collaborators undertook additional analyses using Centers for Medicare & Medicaid Services (CMS) Medicare data to further investigate the potential risk of GBS following RZV. Concurrently, epidemiologic data suggested a potentially elevated risk of GBS following HZ in U.S. adults. Using data from these sources and a published simulation model, this study evaluated the health benefits and risks associated with vaccinating immunocompetent adults ≥50 y with RZV compared to no vaccination. In the base case analysis, RZV vaccination averted 43,000-63,000 cases of HZ, including GBS complications, per million vaccinated per 10-y age cohort compared to 3-6 additional cases of GBS projected following RZV per million vaccinated in the same population. This analysis highlights the projected health benefits of RZV vaccination compared to the relatively low potential risk of GBS following RZV.

Severe Acute Respiratory Infection (SARI) sentinel surveillance in the country of Georgia, 2015-2017.

BACKGROUND: Severe Acute Respiratory Infection (SARI) causes substantial mortality and morbidity worldwide. The country of Georgia conducts sentinel surveillance to monitor SARI activity and changes in its infectious etiology. This study characterizes the epidemiology of SARI in Georgia over the 2015/16 and 2016/17 influenza seasons, compares clinical presentations by etiology, and estimates influenza vaccine effectiveness using a test-negative design. METHODS: SARI cases were selected through alternate day systematic sampling between September 2015 and March 2017 at five sentinel surveillance inpatient sites. Nasopharyngeal swabs were tested for respiratory viruses and Mycoplasma pneumoniae using a multiplex diagnostic system. We present SARI case frequencies by demographic characteristics, co-morbidities, and clinical presentation, and used logistic regression to estimate influenza A vaccine effectiveness. RESULTS: 1,624 patients with SARI were identified. More cases occurred in February (28.7%; 466/1624) than other months. Influenza was the dominant pathogen in December-February, respiratory syncytial virus in March-May, and rhinovirus in June-November. Serious clinical symptoms including breathing difficulties, ICU hospitalization, and artificial ventilation were common among influenza A and human metapneumovirus cases. For influenza A/H3, a protective association between vaccination and disease status was observed when cases with unknown vaccination status were combined with those who were unvaccinated (OR: 0.53, 95% CI: 0.30, 0.97). CONCLUSIONS: Multi-pathogen diagnostic testing through Georgia's sentinel surveillance provides useful information on etiology, seasonality, and demographic associations. Influenza A and B were associated with more severe outcomes, although the majority of the population studied was unvaccinated. Findings from sentinel surveillance can assist in prevention planning.

Vaccination legislation in Latin America and the Caribbean.

Governments have the authority and responsibility to ensure vaccination for all citizens. The development of vaccination legislation in Latin America and the Caribbean (LAC) parallels the emergence of sustainable, relatively autonomous, and effective national immunization programs. We reviewed vaccination legislation and related legal documents from LAC countries (excluding Canada, Puerto Rico, the United States, and the US Virgin Islands), and described and assessed vaccination legislation provisions. Twenty-seven of the 44 countries and territories in the Region have proposed or enacted vaccination legislation. Provisions vary substantially, but legal frameworks generally protect the sustainability of the immunization program, the individual's right to immunization, and the state's responsibility to provide it as a public good. Of the legislation from countries and territories included in the analysis, 44 per cent protects a budget line for vaccines, 96 per cent mandates immunization, 63 per cent declares immunization a public good, and 78 per cent explicitly defines the national vaccine schedule. We looked for associations between vaccination legislation in LAC and national immunization program performance and financing, and conclude with lessons for governments seeking to craft or enhance vaccination legislation.

TRIVAC decision-support model for evaluating the cost-effectiveness of Haemophilus influenzae type b, pneumococcal and rotavirus vaccination.

The TRIVAC decision support model has been used widely in Latin America and other regions to help national teams evaluate the cost-effectiveness of Haemophilus influenzae type b (Hib) vaccine, pneumococcal conjugate vaccine (PCV) and rotavirus vaccine (RV). We describe the structure and functioning of this model, and identify the parameters with the greatest influence on the results. The TRIVAC model is a spreadsheet software program that calculates incremental cost-effectiveness ratios (ICERs) and other indicators for three childhood vaccines (Hib, PCV and RV) utilising parameters such as demography, disease burden, vaccine costs, vaccine coverage, vaccine efficacy, health service utilisation and costs. There is a good deal of uncertainty about the local values of many of the parameters that have most influence on the cost-effectiveness of these new vaccines. Cost-effectiveness models can be used to explore the implications of different values of these parameters. However, for such models to be seen as relevant and helpful by decision-makers, they need to be transparent, flexible, easy to use, and embedded in a process which is owned and led by national teams. In this paper the key drivers of cost-effectiveness in the model are identified by one-way sensitivity analyses, run for each vaccine in 147 countries. The data used are mainly from standard international sources and the published literature. The primary indicator was the discounted cost per Disability Adjusted Life-Year (DALY) averted, from a government perspective, over a 20-year period (2013-2032). For all three vaccines, the ICER was most sensitive to changes in relative coverage (the coverage of the children who would have become diseased or, more importantly, died if the population had not been vaccinated, as a % of overall national coverage) and the herd effect multiplier. Other influential parameters for all three vaccines were: the incidence and case fatality of disease, the baseline trend in disease mortality in the absence of vaccination, vaccine efficacy, vaccine price and the % decline in vaccine price per year. Important vaccine-specific parameters included the cost of Hib meningitis sequelae, PCV serotype coverage and the rotavirus gastro-enteritis (RVGE) admission rate. While vaccine efficacy, herd effects, disease mortality and vaccine price are commonly cited as important drivers of cost-effectiveness, this analysis highlights the potentially important influence of relative coverage, a parameter rarely considered in models of vaccine impact and cost-effectiveness.

Using standardized tools to improve immunization costing data for program planning: the cost of the Colombian Expanded Program on Immunization.

INTRODUCTION: The cost of Expanded Programs on Immunization (EPI) is an important aspect of the economic and financial analysis needed for planning purposes. Costs also are needed for cost-effectiveness analysis of introducing new vaccines. We describe a costing tool that improves the speed, accuracy, and availability of EPI costs and that was piloted in Colombia. METHODS: The ProVac CostVac Tool is a spreadsheet-based tool that estimates overall EPI costs considering program inputs (personnel, cold chain, vaccines, supplies, etc.) at three administrative levels (central, departmental, and municipal) and one service delivery level (health facilities). It uses various costing methods. The tool was evaluated through a pilot exercise in Colombia. In addition to the costs obtained from the central and intermediate administrative levels, a survey of 112 local health facilities was conducted to collect vaccination costs. Total cost of the EPI, cost per dose of vaccine delivered, and cost per fully vaccinated child with the recommended immunization schedule in Colombia in 2009 were estimated. RESULTS: The ProVac CostVac Tool is a novel, user-friendly tool, which allows users to conduct an EPI costing study following guidelines for cost studies. The total costs of the Colombian EPI were estimated at US$ 107.8 million in 2009. The cost for a fully immunized child with the recommended schedule was estimated at US$ 153.62. Vaccines and vaccination supplies accounted for 58% of total costs, personnel for 21%, cold chain for 18%, and transportation for 2%. Most EPI costs are incurred at the central level (62%). The major cost driver at the department and municipal levels is personnel costs. CONCLUSION: The ProVac CostVac Tool proved to be a comprehensive and useful tool that will allow researchers and health officials to estimate the actual cost for national immunization programs. The present analysis shows that personnel, cold chain, and transportation are important components of EPI and should be carefully estimated in the cost analysis, particularly when evaluating new vaccine introduction.

Performing Country-led Economic Evaluations to Inform Immunization Policy: ProVac Experiences in Latin America and the Caribbean.

New vaccines have been demonstrated to be effective in reducing morbidity and mortality, particularly in children, but come at increased costs to societies, governments, and their national immunization programs compared with other traditional childhood vaccines. Rational allocation of available resources requires systematic collection of the evidence base to decide whether to introduce a new vaccine, an important component of which is cost-effectiveness analysis. In this article, we develop in-depth case studies to examine the country experience of conducting cost-effectiveness analysis with the support of Pan American Health Organization ProVac Initiative and the implications of its process for decision making on new vaccine introduction in Latin America and the Caribbean. Key lessons regarding how cost-effectiveness analysis may be effectively used to inform evidence-based immunization policy are highlighted, drawing from the experience of Nicaragua and Paraguay. Based on the lessons identified, the vision going forward will focus on promoting the sustainability of multidisciplinary country teams while continuing to prioritize capacity development as an overarching guiding principle for preparing countries to face future new vaccine policy decisions.