Cost-effectiveness of meningococcal vaccination of Norwegian teenagers with a quadrivalent ACWY conjugate vaccine

Cost-effectiveness analysis of vaccination strategies against meningococcal disease for children under nine years of age in China

Meningococcal vaccination strategies in China are intricate, including multiple vaccines targeting different serogroups. The current National Immunization Program (NIP) includes two polysaccharide vaccines for serogroups A and C (MPV-A and MPV-AC), covering limited serogroups and requiring adaptation. This study aims to evaluate the cost-effectiveness of replacing the current strategy with alternative strategies utilizing non-NIP vaccines to inform policy decisions. From a societal perspective, a decision tree-Markov model was constructed to simulate the economic and health consequences of meningococcal disease in a 2019 birth cohort with four vaccination strategies. Epidemiology, vaccine efficacy, cost, and other parameters were derived from previous studies. We conducted sensitivity analyses to assess the robustness of the findings and explored prices for non-NIP vaccines that enable cost-effective strategies. Compared to the current strategy, alternative strategies using quadrivalent polysaccharide vaccine (MPV-4), bivalent conjugate vaccine (MCV-AC), and quadrivalent conjugate vaccine (MCV-4) could avoid 91, 286, and 455 more meningococcal cases. The ICERs were estimated at approximately $250 thousand/QALY, $450 thousand/QALY, and $1.5 million/QALY, all exceeding the threshold of three times GDP per capita. The alternative strategies were not cost-effective. However, if vaccine prices were reduced to $3.9 for MPV-4, $9.9 for MCV-AC, and $12 for MCV-4, the corresponding strategy would be cost-effective. The current meningococcal vaccination strategy in China could effectively prevent the disease at a low cost, but with limited serogroup coverage. Strategies using MPV-4, MCV-AC, or MCV-4 could increase health benefits at a substantial cost, and might become cost-effective if vaccine prices decrease.

Monophosphoryl Lipid A-based Adjuvant to Promote the Immunogenicity of Multivalent Meningococcal Polysaccharide Conjugate Vaccines

Activation of the adaptive immune system requires the engagement of costimulatory pathways in addition to B and T cell Ag receptor signaling, and adjuvants play a central role in this process. Many Gram-negative bacterial polysaccharide vaccines, including the tetravalent meningococcal conjugate vaccines (MCV4) and typhoid Vi polysaccharide vaccines, do not incorporate adjuvants. The immunogenicity of typhoid vaccines is due to the presence of associated TLR4 ligands in these vaccines. Because the immunogenicity of MCV4 is poor and requires boosters, I hypothesized that TLR4 ligands are absent in MCV4 and that incorporation of a TLR4 ligand-based adjuvant would improve their immunogenicity. Consistent with this hypothesis, two Food and Drug Administration-approved MCV4 vaccines, MENVEO and MenQuadfi, lack TLR4 ligands. Admixing monophosphoryl lipid A, a TLR4 ligand-based adjuvant formulation named "Turbo" with MCV4 induced significantly improved IgM and IgG responses to all four meningococcal serogroup polysaccharides in adult and aged mice after a single immunization. Furthermore, in infant mice, a single booster was sufficient to promote a robust IgG response and 100% seroconversion when MCV4 was adjuvanted with Turbo. Turbo upregulated the expression of the costimulatory molecules CD40 and CD86 on B cells, and Turbo-driven adjuvanticity is lost in mice deficient in CD40 and CD86. These data suggest that Turbo induces the required costimulatory molecules for its adjuvant activity and that incorporation of Turbo could make bacterial polysaccharide vaccines more immunogenic, minimize booster requirements, and be cost-effective, particularly for those individuals in low- and middle-income and disease-endemic countries.

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.

Efficacy and Safety of Quadrivalent Conjugate Meningococcal Vaccines: A Systematic Review and Meta-Analysis

Over the last decades, different quadrivalent antimeningococcal vaccine formulations (diphteria toxoid conjugate, MenACWY-D; tetanus toxoid conjugate, MenACWY-TT; CRM₁₉₇ protein conjugate, MenACWY-CRM) have been developed. However, their availability varies, both in terms of authorized formulations and of inclusion in vaccination schedules. Furthermore, several countries include only the monovalent meningococcal C (MenC) vaccine in their immunization programmes. Finally, there is currently no updated systematic review that directly compares the MenACWY formulations. Thus, we summarized the evidence on efficacy and safety through four parallel, independent systematic literature reviews with meta-analysis which included randomized controlled trials comparing the abovementioned vaccines. A total of 16 studies have been included. In terms of efficacy, MenACWY-TT outperformed MenACWY-D and MenACWY-CRM for A, W-135, and Y serogroups, while no significant difference was found for serogroup C. Furthermore, we did not find significant differences in efficacy between MenC and MenACWY-TT. Regarding the safety, we were able to perform a quantitative analysis only between MenACWY-TT and MenC, finding no significant differences. Similarly, among the different MenACWY formulations no relevant differences were identified. These findings suggest that MenACWY-TT could be preferable to other formulations to improve current vaccination programs and to better develop future immunization policies.

Cost-utility analysis of the universal pneumococcal vaccination programme for older adults in Norway

The aim of this study was to establish whether the universal pneumococcal vaccination for older adults in Norway is likely to be cost-effective from the perspective of the health care provider. A decision tree model developed by the Public Health Agency of Sweden was adapted to the Norwegian setting. Two cohorts, consisting of 65-year-olds and 75-year-olds grouped into vaccinated and unvaccinated, were followed over a 5-year time horizon. In the base case, the 23-valent polysaccharide vaccine (PPV23) was used while the 13-valent pneumococcal conjugate vaccine (PCV13) was included in scenario analyses only. The costs and health benefits (measured in quality adjusted life years (QALY) gained) were compared in the two cohorts between the vaccinated and unvaccinated groups. The impact of indirect effects of the vaccine, such as herd immunity and serotype replacement, were not investigated. The relative importance of change in price was assessed by performing one-way sensitivity analyses. Under base-case assumptions, the programme for the 75-year-old cohort is expected to be dominant (cost-effective) from the health care perspective at the current maximal pharmacy retail price and at 75% vaccination coverage. In comparison, for the 65-year-old cohort the cost per QALY gained is approximately NOK 601,784 (EUR 61,281) under the base-case assumptions. A reduction in the cost of the vaccine to one quarter of its current level also brings the cost per QALY gained within the acceptable ranges in a Norwegian context for both the 65- and 75-year-old cohorts. There is no exact cost-effectiveness threshold in Norway. However, introducing a vaccination programme against pneumococcal disease for 65-year-olds in Norway is likely to fall within the acceptable range while for the 75-year-old cohort the universal programme appears to be dominant (cost-effective).