Cost-effectiveness of alternative strategies for vaccination of adolescents against serogroup B IMD with the MenB-FHbp vaccine in Canada

Accounting for Adverse Events Following Immunization in Economic Evaluation: Systematic Review of Economic Evaluations of Pediatric Vaccines Against Pneumococcus, Rotavirus, Human Papillomavirus, Meningococcus and Measles-Mumps-Rubella-Varicella

OBJECTIVES

Economic evaluations of vaccines should accurately represent all relevant economic and health consequences of vaccination, including losses due to adverse events following immunization (AEFI). We investigated to what extent economic evaluations of pediatric vaccines account for AEFI, which methods are used to do so and whether inclusion of AEFI is associated with study characteristics and the vaccine's safety profile.

METHODS

A systematic literature search (MEDLINE, EMBASE, Cochrane Systematic Reviews and Trials, Database of the Centre for Reviews and Dissemination of the University of York, EconPapers, Paediatric Economic Database Evaluation, Tufts New England Cost-Effectiveness Analysis Registry, Tufts New England Global Health CEA, International Network of Agencies for Health Technology Assessment Database) was performed for economic evaluations published between 2014 and 29 April 2021 (date of search) pertaining to the five groups of pediatric vaccines licensed in Europe and the United States since 1998: the human papillomavirus (HPV) vaccines, the meningococcal vaccines (MCV), the measles-mumps-rubella-varicella (MMRV) combination vaccines, the pneumococcal conjugate vaccines (PCV) and the rotavirus vaccines (RV). Rates of accounting for AEFI were calculated, stratified by study characteristics (e.g., region, publication year, journal impact factor, level of industry involvement) and triangulated with the vaccine's safety profile (Advisory Committee on Immunization Practices [ACIP] recommendations and information on safety-related product label changes). The studies accounting for AEFI were analyzed in terms of the methods used to account for both cost and effect implications of AEFI.

RESULTS

We identified 112 economic evaluations, of which 28 (25%) accounted for AEFI. This proportion was significantly higher for MMRV (80%, four out of five evaluations), MCV (61%, 11 out of 18 evaluations) and RV (60%, nine out of 15 evaluations) compared to HPV (6%, three out of 53 evaluations) and PCV (5%, one out of 21 evaluations). No other study characteristics were associated with a study's likelihood of accounting for AEFI. Vaccines for which AEFI were more frequently accounted for also had a higher frequency of label changes and a higher level of attention to AEFI in ACIP recommendations. Nine studies accounted for both the cost and health implications of AEFI, 18 studies considered only costs and one only health outcomes. While the cost impact was usually estimated based on routine billing data, the adverse health impact of AEFI was usually estimated based on assumptions.

DISCUSSION

Although (mild) AEFI were demonstrated for all five studied vaccines, only a quarter of reviewed studies accounted for these, mostly in an incomplete and inaccurate manner. We provide guidance on which methods to use to better quantify the impact of AEFI on both costs and health outcomes. Policymakers should be aware that the impact of AEFI on cost-effectiveness is likely to be underestimated in the majority of economic evaluations.

Potential public health impact of a Neisseria meningitidis A, B, C, W, and Y pentavalent vaccine in the United States

Objective: Globally, 5 serogroups (A, B, C, W, and Y) cause the majority of invasive meningococcal disease (IMD). Vaccines targeting these serogroups are currently part of the US adolescent immunization platform, which includes 1 + 1 dosing of a MenACWY vaccine routinely at ages 11 and 16 years and 2 doses of a MenB vaccine at age 16-23 years under shared clinical decision-making between the patient and healthcare provider. In 2018, MenACWY vaccination coverage was 86.6% for ≥1 dose and 50.8% for ≥2 doses, whereas MenB vaccination coverage was 17.2% for ≥1 dose and <50% for completion of the multidose series. A pentavalent MenABCWY vaccine could simplify immunization schedules and improve vaccination coverage. We estimated the public health impact of a pentavalent MenABCWY vaccine using a model that considers meningococcal carriage and vaccination coverage.Methods: A population-based dynamic model estimated the 10-year reduction in IMD from implementing a MenABCWY vaccine within the existing US meningococcal immunization platform. Five vaccination schedules (4 new, 1 existing) were examined to estimate the impact of different recommendations on the overall reduction in the number of IMD cases. Sensitivity analyses were performed by varying vaccination coverage at age 16 years.Results: The existing schedule and coverage of MenACWY and MenB vaccines (total 4 doses) could potentially avert 165 IMD cases over 10 years versus no vaccination. Assuming similar MenABCWY and MenACWY vaccination coverage rates at age 16 years, replacing 1 or more MenACWY and/or MenB doses with MenABCWY could avert more cases, ranging from 189 to 256. The most beneficial MenABCWY vaccine schedule was 2 doses at age 11 years and 1 dose at age 16 years.Conclusions: Replacing one or more MenACWY/MenB vaccine doses with MenABCWY could reduce IMD caused by all 5 meningococcal serogroups among the US adolescent population, while also reducing the number of injections required.

Review of clinical studies comparing meningococcal serogroup C immune responses induced by MenACWY-TT and monovalent serogroup C vaccines

Many countries are replacing meningococcal serogroup C (MenC) conjugate vaccines (MCCV) with quadrivalent conjugate (MenACWY) vaccines, such as MenACWY-TT (Nimenrix®). This review examined eight studies comparing MenC immune responses induced by MenACWY-TT and MCCV to determine if these data support these changes. MenC serum bactericidal antibody levels using human (hSBA) or rabbit complement (rSBA) were evaluated at ~1 month postvaccination. Overall, ≥98.4% of infants administered 2 + 1 MenACWY-TT or MCCV schedules had rSBA titers ≥1:8 postprimary and postbooster vaccination; hSBA titers ≥1:8 were similar. In toddlers administered single MenACWY-TT or MCCV doses, ≥97.3% had rSBA titers ≥1:8 postvaccination; percentages with hSBA titers ≥1:8 were higher post-MenACWY-TT. Of children and adolescents receiving primary and booster MenACWY-TT and MCCV, ≥98.6% had rSBA titers ≥1:8; all children receiving MenACWY-TT or MCCV booster had hSBA titers ≥1:8 postdosing. MenC immune responses induced by MenACWY-TT are robust and generally comparable/superior to MCCV, supporting changes to recommendations.

Use of Cost-Effectiveness Analyses for Decisions About Vaccination Programs for Meningococcal Disease in the United States, United Kingdom, The Netherlands, and Canada

INTRODUCTION

Meningococcal vaccines to protect against invasive meningococcal disease (IMD) vary in terms of vaccine technology and serogroup coverage (Polysaccharide MnACWY, conjugated C and ACWY, outer membrane vesicle-based or protein-based B vaccines), and the national recommendations for each of them vary in terms of target population and number of doses. We sought to understand factors associated with the evolution of meningococcal vaccination program recommendations in four countries with formal evaluation processes: the UK, US, the Netherlands, and Canada.

AREAS COVERED

A targeted review of published literature and internet sources for the four countries relating to meningococcal vaccination decision-making was conducted. The review focused on the impact of cost-effectiveness analyses on vaccine policy decisions and the extent to which variation in incidence of IMD and its potential catastrophic consequences influenced policy decisions.The evolution of meningococcal vaccine recommendations in the four countries was mainly driven by changes in vaccine availability and changes in serogroup incidence. Public pressure due to the catastrophic nature of IMD influenced recommendations. The role of cost-effectiveness analyses varied across the 4 countries.

EXPERT OPINION

The value of implementing meningococcal vaccination programs should be assessed using factors beyond those included in traditional cost-effectiveness analyses.

Why the Anti-Meningococcal B Vaccination during Adolescence Should Be Implemented in Italy: An Overview of Available Evidence

Although meningococcal disease has a low incidence in Italy, it is a public health concern owing to its high lethality rate and high frequency of transitory and/or permanent sequelae among survivors. The highest incidence rates are recorded in infants, children and adolescents, and most of the cases are due to Neisseria meningitidis B. In Italy, anti-meningococcal B (anti-MenB) vaccination is free for infants but, despite the considerable disease burden in adolescents, no national recommendation to vaccinate in this age-group is currently available. The aim of this study was to assess the main available scientific evidence to support the Italian health authorities in implementing a program of free anti-MenB vaccination for adolescents. We conducted an overview of the scientific literature on epidemiology, disease burden, immunogenicity and safety of available vaccines, and economic evaluations of vaccination strategies. Each case of invasive meningococcal disease generates a considerable health burden (lethality rate: 9%; up to 60% of patients experience at least one sequela) in terms of impaired quality of life for survivors and high direct and indirect costs (the mean overall cost of acute phase for a single case amounts to about EUR 13,952; the costs for post-acute and the long-term phases may vary widely depending of the type of sequela, reaching an annual cost of about EUR 100,000 in cases of severe neurological damage). Furthermore, vaccination against meningococcus B in adolescence proved cost-effective. The study highlights the need to actively offer the anti-MenB vaccination during adolescence at a national level. This would make it possible to avoid premature deaths and reduce the high costs borne by the National Health Service and by society of supporting survivors who suffer temporary and/or permanent sequelae.