Expert Review of Vaccines最新文献

Background: The ongoing emergence of SARS-CoV-2 variants has raised concerns about the breadth of the immune response provided by existing vaccines.

Research design and methods: In this study, participants aged 18-75 years with no prior COVID-19 infection or vaccination history were enrolled to receive the CoronaVac vaccine. The interval between the first and second vaccine doses was 28 days, while the third dose was given 6 months after the second.

Results: Between February 1 to 15 February 2022, we recruited 40 eligible participants who had not received any COVID-19 vaccination and had no prior COVID-19 infection. After the third dose, neutralizing antibody levels significantly increased against the ancestral strain and certain Omicron variants (BA.1, BA.4/5, BF.7). Compared to levels observed 28 days post-second dose, neutralizing antibody levels rose further 28 days after the third dose, with the GMFI against the ancestral strain at 1.69 (95% CI: 1.27, 2.20). Among other variants, the GMFI against Omicron variants (BA.1, BA.4/5, BF.7) exceeded that for Beta and Delta, with the highest GMFI recorded for the BA.4/5 variant at 4.97 (95% CI: 3.08, 8.05).

Conclusions: The necessity of the third booster dose lies in its ability to enhance the breadth of the immune response.

Introduction: Comparative effectiveness data of COVID-19 vaccines remain limited. We conducted a systematic review and network meta-analysis (NMA) feasibility assessment of effectiveness studies of Omicron-adapted COVID-19 vaccines.

Research design and methods: Searches in MEDLINE and Embase up to February 2025 identified studies comparing the effectiveness of Omicron-adapted COVID-19 vaccines, either directly or against no recent vaccine. Two investigators independently selected articles reporting adjusted vaccine effectiveness (VE). A feasibility assessment determined the appropriateness of a common comparator and evaluated effect modifiers (EMs). Data extraction and risk-of-bias assessment were performed by one investigator and validated by a second investigator. Bayesian NMAs using random-effects models were performed for base-case analyses, data permitting.

Results: The review identified 25 studies for Omicron-adapted COVID-19 vaccines: 16 for XBB formulations, eight of which were included in NMAs, all for mRNA formulations, representing 29.9 million participants. BNT162b2 had the largest evidence base. Comparisons between XBB.1.5-adapted BNT162b2 (Comirnaty) and mRNA-1273 (Spikevax) found that both vaccines are effective and comparable against XBB-related hospitalizations, infections, and medically attended visits in adults Among elderly, the estimated effectiveness against XBB-related hospitalizations favored BNT162b2.

Conclusions: Findings of this NMA of observational studies support the effectiveness of XBB.1.5-adapted mRNA vaccines. Limitations included assumptions on EMs and sparse evidence networks.

Introduction: Immunization Information Systems (IISs) are essential public health tools, supporting the management and analysis of vaccination data to aid clinical and strategic decision-making.

Methods: Following PRISMA guidelines, this systematic review investigated global state and operational characteristics of IISs. A comprehensive search across multiple databases up to 6^th of June 2023, identified 2,612 articles, with 238 included.

Results: A significant increase in IIS research was observed in recent years, with a strong preference (84.5%) for electronic immunization registers (EIRs). Notably, 36% of IISs operate at the national level, and 47.7% meet the U.S. CDC definition, 17.0% are interoperable with personal health records, and 11.7% provide direct access to vaccination data for vaccinees or their guardians. Other key features include automated reminder systems for recipients and providers (12.1%), near real-time or real-time data entry (11.0%), the inclusion of demographic and socioeconomic data (16.7%), and the capacity to document vaccine refusal or hesitancy (10.2%).

Conclusions: IISs contribute to improving population-level surveillance of vaccine-preventable diseases. Persistent limitations related to data standardization, interoperability, and cost-effectiveness evaluation must be addressed. Strengthening these aspects is crucial to fully harness the potential of IISs in various healthcare settings, where enhanced vaccination tracking and targeting are most urgently needed.

Introduction: Recombinant Zoster Vaccine (RZV) is recommended for Herpes Zoster (HZ) prevention in high-risk patients over 18 years of age.

Research design and methods: This is a prospective population-based study conducted over a three-year period in a Southern Italian General Hospital. The study population was represented by RZV recipients with diverse chronic comorbidities. Adverse Events Following Immunization (AEFIs), baseline disease flares and post-vaccination HZ episodes were evaluated through sequential follow-ups conducted 7 days, 3 months, and 3-38 months post-vaccination, respectively.

Results: Study population included 787 RZV recipients, mostly affected by onco-hematological, cardiovascular and rheumatological disorders. The AEFIs reporting rate was 44.15%. The most frequent symptoms were injection site pain/itching (37.19%), asthenia/malaise (12.74%) and fever (10.30%). Three serious AEFIs with consistent causal association with vaccination were recorded (0.22%), all of which underwent full recovery. Sixteen patients (2.37%) experienced a baseline condition flare-up within 3 months (mean interval 33.88 ± 24.88 days). Multiple baseline disorders (OR:1.97; 95%CI:1.37-2.83; p-value < 0.001) and rheumatological conditions (OR:11.67; 95%CI:2.00-68.27; p-value < 0.01) increased flare risk, while male sex decreased it. Twenty-six vaccinees manifested HZ post-vaccination (cumulative incidence rate 5.05/100,000 person-days), with particularly increased incidence in patients with recurrent/severe HZ history (IRR:14.35; 95%CI:5.64-34.04; p-value < 0.001).

Conclusion: The study demonstrates RZV safety and HZ protection in vulnerable patients, consistently with available evidence.

Background: Vaccine hesitancy among healthcare workers (HCWs) is a global concern, needing reliable tools to measure HCW vaccine confidence. We adapted and validated the 10-item 'iPro-VC-Be' tool for the Nigerian context.

Research design and methods: We conducted a 3-step process. First, contextual adaptation using expert round-table discussions and cognitive interviews with HCWs in Oyo and Jigawa States (12/2023-05/2024). Second, translation and back-translation to Hausa, Igbo and Yoruba, including HCW group discussions (05/2024). Finally, testing validity in all languages, using a test-retest approach (06/2024-09/2024).

Results: Sixty-four participants contributed to adaptation, 25 researchers and 39 HCWs supported translations, 435 HCWs completed the first survey, and 263 completed the re-test. Of the 10 iPro-VC-Be items, 3 were unchanged, 6 had language edits, and 1 was replaced. The Cronbach's alpha indicated good internal reliability, and overall the intraclass correlation coefficient indicated moderate re-test reliability. Confirmatory factor analysis supported goodness of fit across multiple indices, but one negatively framed item performed poorly. Items assessing confidence in vaccines and trust in government were significantly associated with HCW vaccine uptake.

Conclusion: The adapted iPro-VC-Be was valid, however, we recommend using a shorter 6-item version for Nigeria that does not include items linked to immunization resources.

Background: Clinical trials have compared new pneumococcal conjugative vaccines (PCVs; PCV15 and PCV20) to an established PCV (PCV13) in a routine 2 + 1 schedule. This study performed an indirect comparison of PCV15 vs. PCV20 immune responses in healthy infants and toddlers.

Research design and methods: Pooled, matching-adjusted PCV15 trials were indirectly compared to the analogous PCV20 trial for IgG response rate difference (RRD) and geometric mean concentration ratio (GMR) at the post-primary series (PPS) and post-toddler dose (PTD) timepoints.

Results: At PPS, PCV15 was non-inferior for RRD and GMR as compared to PCV20 for all PCV13 serotypes. Moreover, PCV15 was superior to PCV20 for the RRDs of serotypes 1, 3, 4, 5, 6B, 9V, and 23F and GMRs of serotypes 3, 4, 5, 6B, 9V, and 23F at PPS. At PTD, RRDs were comparable for all PCV13 serotypes, except serotype 3, for which PCV15 was superior. PCV15 was superior for the GMRs of serotypes 3, 6B, and 23F, and comparable for the remaining serotypes at PTD. RRDs for serotypes 22F and 33F were non-inferior at both PPS and PTD.

Conclusion: In a 2 + 1 schedule, PCV15 demonstrates immunogenicity comparable or superior to PCV20 across PCV13 serotypes, especially for serotype 3.

Background: Pharmacies can increase access to vaccines. This study aimed to describe trends in the proportion of adolescent and adult vaccinations administered in pharmacies in the United States from 2018 to 2024.

Research design and methods: This was a retrospective cross-sectional analysis of medical and pharmacy claims from commercial health insurance enrollees. We recorded vaccinations received by enrollees ≥9 years of age from 2018 to 2023 (routine vaccines) or 2024 (seasonal vaccines). We calculated the annual proportion of vaccinations occurring in pharmacies and the accumulated percent change in vaccination rate during each year from 2020 onward compared to 2018-2019.

Results: The proportion of routine vaccinations occurring in pharmacies was higher among adults than among adolescents. For most routine vaccines, this proportion increased during the study period. The lowest proportion was observed for adolescent human papillomavirus vaccination in 2018 (0.2%), and the highest for herpes zoster vaccination among adults ≥65 years of age in 2023 (88.6%). For all age groups, pharmacy-based vaccination was more common for seasonal influenza and SARS-CoV-2 vaccines than for all routine vaccines except herpes zoster.

Conclusions: Pharmacy-based vaccination is increasingly common in the United States, particularly among adults and for seasonal vaccines, and can help increase the overall level of vaccine uptake.

Background: We analyzed the impact of non-pharmacological interventions (NPIs) and PCV13 inoculation on nasopharyngeal (NP) carriage of Staphylococcus aureus (Sa), Streptococcus pneumoniae (Sp), Moraxella catarrhalis (Mc), and Haemophilus influenzae (Hi) in healthy children under 5-years-old in Beijing, China.

Research design and methods: NP swabs were taken from healthy children seeking routine well-child care at the pediatric preventive health clinic. NP swabs were frozen in Tryptic Soy Broth (TSB) medium and stored at -80°C, and bacterial was detected by culture.

Results: From December 2019 to November 2021, 1939 children were enrolled, among whom 278 (14.3%) were found to carry Sa isolates, 115 (5.9%) Sp, 39 (2.0%) Mc, and 6 (0.3%) Hi. The carriage of Sa was highest in infants under 6 months, negatively correlated with Sp and Mc. The Sa carriage rate in infants below 6 months of age rose from 26.7% in pre-NPIs to 32.7% in post-NPIs early. The 13-valent pneumococcal conjugate vaccine (PCV13) uptake rose from 42.3% in December 2019 to 62.3% by October 2021.

Conclusions: The broad application of NPIs caused a decline in Sp and Mc carriage among children under 5-years-old,  accompanied by an elevation in the Sa carriage rate among infants.

Background: This study evaluated the impact of various vaccination strategies using an adapted vaccine in Peru.

Research design and methods: Using a previously published combined Markov-decision-tree model adapted for Peru, this study estimated the outcomes of different vaccination strategies targeting various age and risk groups. The model used age-specific epidemiology, clinical, cost, and quality-of-life inputs derived from the published literature and national surveillance data. Sensitivity analyses were conducted to assess uncertainty.

Results: The vaccination strategy targeting older adults aged ≥ 60 years and the high-risk population between 12 and 59 years old with a 24% vaccine uptake was estimated to prevent 78,483 symptomatic cases, 2,962 hospitalizations, 103 deaths, and 2,913 lost QALYs compared with no vaccination, translating to an incremental decrease of $12,856,654 in total direct costs and an incremental decrease of $35,090,748 in total societal costs. These gains were further increased by expanding vaccination to additional age groups and increasing vaccine uptake.

Conclusions: Vaccination in the population aged ≥ 60 years and the high-risk population between 12 and 59 years old in Peru was projected to yield substantial health and economic benefits. The impact could be substantially increased by expanding eligibility to younger age groups and increasing vaccine uptake.