Expert Review of Vaccines最新文献

Background: The aim of this study was to evaluate the public health and economic impact of the COVID-19 booster vaccination with BNT162b2 in Japan during an Omicron-dominant period from early 2022.

Research design and methods: A combined cohort Markov decision tree model estimated the cost-effectiveness of annual or biannual booster vaccination strategies compared to no booster vaccination for those aged 65 years and above, and those aged 60-64 years at high risk as the base case. The societal perspective was primarily considered. We also examined other target populations with different age and risk groups. Sensitivity and scenario analyses with alternative inputs were performed.

Results: Annual and biannual vaccination strategies were dominant from the societal perspective in the base case. Incremental Cost Effectiveness Ratios (ICERs) from the payer perspective were JPY 1,752,499/Quality Adjusted Life Year (QALY) for annual vaccination and JPY 2,831,878/QALY for biannual vaccination, both less than the threshold value in Japan (JPY 5 million/QALY). The results were consistent even when examining other target age and risk groups. All sensitivity and scenario analyses indicated that ICERs were below JPY 5 million/QALY.

Conclusions: Booster vaccination with the COVID-19 vaccine BNT162b2 is a dominant strategy and beneficial to public health in Japan.

Introduction: Following the coronavirus disease pandemic, respiratory mucosal vaccines that elicit both mucosal and systemic immune responses have garnered increasing attention. However, human physiological characteristics pose significant challenges in the evaluation of mucosal immunity, which directly impedes the development and application of respiratory mucosal vaccines.

Areas covered: This study summarizes the characteristics of immune responses in the respiratory mucosa and reviews the current status and challenges in evaluating immune response to respiratory mucosal vaccines.

Expert opinion: Secretory Immunoglobulin A (S-IgA) is a major effector molecule at mucosal sites and a commonly used indicator for evaluating respiratory mucosal vaccines. However, the unique physiological structure of the respiratory tract pose significant challenges for the clinical collection and detection of S-IgA. Therefore, it is imperative to develop a sampling method with high collection efficiency and acceptance, a sensitive detection method, reference materials for mucosal antibodies, and to establish a threshold for S-IgA that correlates with clinical protection. Sample collection is even more challenging when evaluating mucosal cell immunity. Therefore, a mucosal cell sampling method with high operability and high tolerance should be established. Targets of the circulatory system capable of reflecting mucosal cellular immunity should also be explored.

Introduction: In 2005, the United States Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination against invasive meningococcal disease (IMD) caused by serogroups A, C, W, and Y (MenACWY) for all 11-12-year-olds, as well as 2-10-year-olds at high risk. In 2010, a booster dose was recommended for all 16-year-olds, as well as for high-risk patients every 3-5 years. In 2015, optional (as opposed to routine) vaccination against meningococcal serogroup B (MenB) at the preferred age of 16-18 years was recommended (Category B, later changed to shared clinical decision-making). In 2023, a vaccine (MenABCWY) against the five serogroups primarily responsible for IMD in the U.S. became available.

Areas covered: This review summarizes the evolution of public policy that led to each milestone vaccine recommendation, reviews epidemiologic data published following the recommendations, and discusses the current state of meningococcal immunization policy.

Expert opinion: The use of MenABCWY has the potential to consolidate policy, improve coverage rates for the five serogroups, address disparities in vaccination coverage, and simplify vaccine delivery.

Introduction: Hookworms infect about half a billion people worldwide and are responsible for the loss of more than two billion disability-adjusted life years. Mass drug administration (MDA) is the most popular preventive approach, but it does not prevent reinfection. An effective vaccine would be a major public health tool in hookworm-endemic areas.

Areas covered: We highlight recent human studies where vaccination with irradiated larvae and repeated rounds of infection-treatment have induced partial protection. These studies have emphasized the importance of targeting the infective larvae to generate immunity to prevent adult worms from maturing in the gut. We summarize the current status of human and animal model vaccine trials.

Expert opinion: Hookworm infection is endemic in resource-poor developing regions where polyparasitism is common, and vaccine cold chain logistics are complex. Humans do not develop sterile immunity to hookworms, and the elderly are frequently overlooked in MDA campaigns. For all these reasons, a vaccine is essential to create long-lasting protection. The lack of a robust animal model to mimic human hookworm infections is a barrier to the discovery and development of a vaccine, however, there have been major recent advances in human challenge studies which will accelerate the process.

Background: Despite multiple revisions of targets and timelines in polio eradication plans since 1988, including changes in supplemental immunization activities (SIAs) that increase immunity above routine immunization (RI) coverage, poliovirus transmission continues as of 2024.

Methods: We reviewed polio eradication plans and Global Polio Eradication Initiative (GPEI) annual reports and budgets to characterize key phases of polio eradication, the evolution of poliovirus vaccines, and the role of SIAs. We used polio epidemiology to provide context for successes and failures and updated prior modeling to show the contribution of SIAs in achieving and maintaining low polio incidence compared to expected incidence for the counterfactual of RI only.

Results: We identified multiple phases of polio eradication that included shifts in targets and timelines and the introduction of different poliovirus vaccines, which influenced polio epidemiology. Notable shifts occurred in GPEI investments in SIAs since 2001, particularly since 2016. Modeling results suggest that SIAs play(ed) a key role in increasing (and maintaining) high population immunity to levels required to eradicate poliovirus transmission globally.

Conclusions: Shifts in polio eradication strategy and poliovirus vaccine usage in SIAs provide important context for understanding polio epidemiology, delayed achievement of polio eradication milestones, and complexity of the polio endgame.

Introduction: Rotavirus is a leading cause of severe diarrheal disease and death in children under five years of age worldwide. Vaccination is one of the most important public health interventions to reduce this significant burden.

Areas covered: This literature review examined vaccination coverage, hospitalization rate, mortality, genotypic distribution, immunogenicity, cost-effectiveness, and risk versus benefit of rotavirus vaccination in children in South America. Nine out of twelve countries in South America currently include a rotavirus vaccine in their national immunization program with coverage rates in 2022 above 90%.

Expert opinion: Introduction of the rotavirus vaccination has led to a marked reduction in hospitalizations and deaths from diarrheal diseases in children under 5 years, particularly infants under 1 year, in several South American countries. In Brazil, hospitalizations decreased by 59% and deaths by 21% (30-38% in infants). In Peru, hospitalizations in infants fell by 46% and deaths by 37% (56% in infants). Overall, data suggest that rotavirus vaccination has reduced rotavirus deaths by 15-50% in various South American countries. There is some evidence that immunity wanes after the age of 1-year old. Ongoing surveillance of vaccine coverage and changes in morbidity and mortality is important to maximize protection against this disease.

Objectives: We conducted a cost-benefit analysis of the pediatric National Immunization Program (NIP) in Italy.

Methods: An economic model evaluated the benefit-cost ratio (BCR) of the Italian pediatric NIP, including 10 pathogens for mandatory vaccines and 4 pathogens for recommended vaccines for children aged 0-10 years from the healthcare-sector and societal perspectives. Separate decision trees were used to model each vaccine-preventable disease (VPD). The 2020 birth cohort (n = 420,084) was followed over their lifetime; the model projected and compared discounted disease cases, life-years, quality-adjusted life-years (QALYs), and costs (2021 euros) with and without immunization (based on current and pre - vaccine era disease incidence estimates, respectively).

Results: The pediatric NIP was estimated to prevent 1.8 million cases of VPDs and 3,330 deaths, resulting in 45,900 fewer life-years lost and 57,000 fewer QALYs lost. Vaccination costs of €285 million were offset by disease cost savings of €1.6 billion, resulting in a BCR of 5.6 from a societal perspective (BCR = 1.7 from a healthcare-sector perspective). When QALYs gained were valued, the BCR increased to 15.6.

Conclusions: The benefits of the Italian pediatric NIP, including averted disease-related morbidity, mortality, and associated costs, highlight the value of continued investment in pediatric immunization.

Objectives: It is important to assess healthcare providers (HCPs) knowledge, attitudes, perceptions, and preferences towards new pneumococcal vaccines for adults.

Methods: HCPs who met eligibility criteria completed an online survey between March - May 2024 that included a discrete choice experiment (DCE) to elicit preferences.

Results: Among 340 participating HCPs, the average age was 44.9 years old, and the majority were male (55.6%), and White (85.3%). Most HCPs reported that they would support (90.3%) and implement (91.5%) a lower age-based recommendation for pneumococcal vaccines (from adults 65+ years to adults 50+ years). A majority of HCPs would offer a supplemental dose of a pneumococcal vaccine to high-risk adults 19-49 years, at-risk or high-risk adults 50-64 years, and adults 65+ years regardless of risk status to increase protection after completing the recommended series. DCE results showed that coverage of pneumococcal pneumonia and invasive pneumococcal disease (IPD) in adults 65+ years were the two most important attributes in evaluating pneumococcal vaccines.

Conclusions: HCPs preferred a pneumococcal vaccine with increased coverage against pneumococcal pneumonia and IPD, and they supported lowering the age recommendation for pneumococcal vaccination as well as a supplemental vaccine dose to provide additional coverage for adults.

Objectives: Older adults (OA) are at risk of morbidity and mortality from respiratory syncytial virus (RSV), a major cause of seasonal acute respiratory illness. The first RSV vaccine for OA (RSVPreF3 OA) was recently launched in Japan. With the already large and growing OA population in Japan, and limited RSV treatments, prevention is key. The aim of this study was to assess the cost-effectiveness of introducing RSVPreF3 OA for Japanese adults aged ≥60 years.

Methods: A static multicohort Markov model was adapted to assess the cost-effectiveness of a single dose of RSVPreF3 OA versus no vaccination over a three-year time horizon. Deterministic and probabilistic sensitivity analyses were conducted to assess parameter uncertainty.

Results: RSVPreF3 OA vaccination prevented 1,008,499 cases and 6,840 deaths, with 109,119 quality-adjusted life-years (QALYs) gained. The incremental cost-effectiveness ratio was Japanese yen (JPY) 4,180,084/QALY gained from a payer perspective and JPY 4,041,917/QALY gained from a societal perspective (with productivity loss from RSV disease), thus vaccination was considered cost-effective. Base case results were robust to changes in sensitivity and scenario analyses.

Conclusions: RSVPreF3 OA vaccination for adults ≥60 years can provide substantial health benefits and is a cost-effective intervention to reduce the RSV burden in Japan.

Background: The 23-valent pneumococcal polysaccharide vaccine (PPSV23) is used in the Japanese National Immunization Program for older adults and adults with increased risk for pneumococcal disease, however, disease incidence and associated burden remain high. We evaluated the cost-effectiveness of pneumococcal conjugate vaccines (PCVs) for adults aged 65 years and high-risk adults aged 60-64 years in Japan.

Research design and methods: Using a Markov model, we evaluated lifetime costs using societal and healthcare payer perspectives and estimated quality-adjusted life-years (QALYs), and number of prevented cases and deaths caused by invasive pneumococcal disease (IPD) and non-IPD. The base case analysis used a societal perspective.

Results: In comparison with PPSV23, the 20-valent PCV (PCV20) prevented 127 IPD cases 10,813 non-IPD cases (inpatients: 2,461, outpatients: 8,352) and 226 deaths, and gained more QALYs (+0.0015 per person) with less cost (-JPY22,513 per person). All sensitivity and scenario analyses including a payer perspective analysis indicated that the incremental cost-effectiveness ratios (ICERs) were below the cost-effectiveness threshold value in Japan (JPY5 million/QALY).

Conclusions: PCV20 is both cost saving and more effective than PPSV23 for adults aged 65 years and high-risk adults aged 60-64 years in Japan.