Human Vaccines & Immunotherapeutics最新文献

Global COVID-19 vaccination programs effectively contained the fast spread of SARS-CoV-2. Characterizing the immunity status of returned populations will favor understanding the achievement of herd immunity and long-term management of COVID-19 in China. Individuals were recruited from 7 quarantine stations in Guangzhou, China. Blood and throat swab specimens were collected from participants, and their immunity status was determined through competitive ELISA, microneutralization assay and enzyme-linked FluoroSpot assay. A total of 272 subjects were involved in the questionnaire survey, of whom 235 (86.4%) were returning Chinese individuals and 37 (13.6%) were foreigners. Blood and throat swab specimens were collected from 108 returning Chinese individuals. Neutralizing antibodies against SARS-CoV-2 were detected in ~90% of returning Chinese individuals, either in the primary or the homologous and heterologous booster vaccination group. The serum NAb titers were significantly decreased against SARS-CoV-2 Omicron BA.5, BF.7, BQ.1 and XBB.1 compared with the prototype virus. However, memory T-cell responses, including specific IFN-γ and IL-2 responses, were not different in either group. Smoking, alcohol consumption, SARS-CoV-2 infection, COVID-19 vaccination, and the time interval between last vaccination and sampling were independent influencing factors for NAb titers against prototype SARS-CoV-2 and variants of concern. The vaccine dose was the unique common influencing factor for Omicron subvariants. Enhanced immunity against SARS-CoV-2 was established in returning Chinese individuals who were exposed to reinfection and vaccination. Domestic residents will benefit from booster homologous or heterologous COVID-19 vaccination after reopening of China, which is also useful against breakthrough infection.

The immune response to heterologous coronavirus disease (COVID-19) vaccination in people living with HIV (PLWH) is still unclear. Herein, our prospective cohort study aimed to compare the immune response of heterologous vaccination with CoronaVac (Sinovac) and Vaxzevria (AstraZeneca) between PLWH having CD4 counts ≤ 200 cells/µL (low CD4+) and > 200 cells/µL (high CD4+). Anti-receptor-binding domain (RBD) immunoglobulin G (IgG) levels and the percentage inhibition of neutralizing antibodies (nAbs) were analyzed at 2 and 12 weeks after immunization. Participants in the low and high CD4+ groups had mean CD4+ counts of 139 and 575 cell/µL, respectively. Two and 12 weeks after immunization, in the low CD4 group, the median anti-RBD-IgG levels were 159 IU/mL and 143 IU/mL, respectively, whereas the nAb level was 71% and decreased to 47.2%, respectively. Contrarily, the median anti-RBD-IgG levels in the high CD4+ group were 273 IU/mL and 294 IU/mL, respectively, whereas the nAb levels were 89.3% and relatively stable at 81.6%. However, although immune responses between the two study groups were not significantly different, a decline in nAb levels was observed at 12 weeks in the low CD4+ group. Therefore, a COVID-19 booster vaccine dose is suggested for immunoprotection.

The mechanisms of Pythium insidiosum-antigen (PIA) immunotherapy activating a patient's immune system are unknown. We evaluated the interleukin-8 (IL-8) serum levels during P. insidiosum infection and after vaccination with PIA in vascular pythiosis cases. Furthermore, we studied the anti-P. insidiosum activity of neutrophils stimulated with various concentrations of PIA ex vivo in 3 strains of P. insidiosum isolated from vascular pythiosis patients. IL-8 serum levels were evaluated using the ELISA technique. We assessed the effect of PIA-stimulated neutrophils on the viability of zoospores using MTT assay, visualized neutrophil extracellular trap (NET) formation via microscopy, and measured the levels of double-stranded DNA (dsDNA) using PicoGreen dsDNA quantitation assay in 3 strains of P. insidiosum isolated from vascular pythiosis patients. Serum levels of IL-8 gradually lowered from the early to the end phases of vaccination with PIA among the surviving group of vascular pythiosis cases. Neutrophils stimulated with 0.01 µg/ml PIA reduced zoospore viability significantly compared to PIA-unstimulated neutrophils for strain 1 and strain 3 (p < .05). Neutrophils stimulated with 0.01, 0.1, 1, and 10 µg/ml PIA exhibited significantly lower zoospore viability than PIA-unstimulated neutrophils for strain 2 (p < .05). IL-8 can be used as a biomarker for monitoring vascular pythiosis cases treated with the PIA vaccine. Also, anti-P. insidiosum activity of PIA-stimulated neutrophils was probably due to the disruption of cellular activity in zoospores rather than the mechanisms based on the formation of NETs.

Current influenza vaccines could be augmented by including recombinant neuraminidase (rNA) protein antigen to broaden protective immunity and improve efficacy. Toward this goal, we investigated formulation conditions to optimize rNA physicochemical stability. When rNA in sodium phosphate saline buffer (NaPBS) was frozen and thawed (F/T), the tetrameric structure transitioned from a "closed" to an "open" conformation, negatively impacting functional activity. Hydrogen deuterium exchange experiments identified differences in anchorage binding sites at the base of the open tetramer, offering a structural mechanistic explanation for the change in conformation and decreased functional activity. Change to the open configuration was triggered by the combined stresses of acidic pH and F/T. The desired closed conformation was preserved in a potassium phosphate buffer (KP), minimizing pH drop upon freezing and including 10% sucrose to control F/T stress. Stability was further evaluated in thermal stress studies where changes in conformation were readily detected by ELISA and size exclusion chromatography (SEC). Both tests were suitable indicators of stability and antigenicity and considered potential critical quality attributes (pCQAs). To understand longer-term stability, the pCQA profiles from thermally stressed rNA at 6 months were modeled to predict stability of at least 24-months at 5°C storage. In summary, a desired rNA closed tetramer was maintained by formulation selection and monitoring of pCQAs to produce a stable rNA vaccine candidate. The study highlights the importance of understanding and controlling vaccine protein structural and functional integrity.

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.

This is a response to Marchand & Masoud's response letter regarding my criticism "Response to Dr. Somovilla del Saz's letter to the editor regarding "Risk of all-cause and cardiac-related mortality after vaccination against COVID-19: A meta-analysis of self-controlled case series studies."" The response is a defense of the initial criticism to the paper regarding the validity of the inclusion of Ladapo´s paper.

Enhanced Passive Safety Surveillance (EPSS) was conducted for quadrivalent inactivated split-virion influenza vaccines (IIV4) in Germany (high dose [HD]) and Finland (standard dose [SD]) for the northern hemisphere (NH) 2022/23 influenza season. The primary objective was to assess adverse events following immunization (AEFI) occurring ≤7 days post-vaccination. In each country, the EPSS was conducted at the beginning of the NH influenza season. Exposure information was documented using vaccination cards (VC), and AEFI were reported via an electronic data collection system or telephone. AEFI were assessed by seriousness and age group (Finland only). The vaccinee reporting rate (RR) was calculated as the number of vaccinees reporting ≥ 1 AEFI divided by the total vaccinees. In Germany, among 1041 vaccinees, there were 31 AEFI (ten vaccinees) during follow-up, including one serious AEFI. Of 16 AEFI (six vaccinees) with reported time of onset, 15 occurred ≤7 days post-vaccination (RR 0.58%, 95% confidence interval [CI] 0.21, 1.25), which was lower than the 2021/22 season (RR 1.88%, 95% CI: 1.10, 3.00). In Finland, among 1001 vaccinees, there were 142 AEFI (51 vaccinees) during follow-up, none of which were serious. Of 133 AEFI (48 vaccinees) with time of onset reported, all occurred ≤7 days post-vaccination (RR 4.80%, 95% CI: 3.56, 6.31), which was similar to the 2021/22 season (RR 4.90%, 95% CI: 3.65, 6.43). The EPSS for HD-IIV4 and for SD-IIV4 in the 2022/23 influenza season did not suggest any clinically relevant changes in safety beyond what is known/expected for IIV4s.

There is an ongoing burden of pneumococcal disease in children despite the use of pneumococcal conjugate vaccines (PCVs). This phase 3, open-label, single-arm, multisite, descriptive study was designed to evaluate the safety and immunogenicity of a 3 + 1 regimen of V114 (VAXNEUVANCE™), a 15-valent PCV, in South Korean infants and toddlers. Adverse events (AEs) were reported for 14 d following any vaccination, and throughout the study period for serious AEs. Serotype-specific immunoglobulin G (IgG) response rates (proportion of participants meeting an IgG threshold value of ≥0.35 μg/mL) and geometric mean concentrations (GMCs) for the 15 serotypes at 30 d postdose 3 (PD3) and at 30 d postdose 4 (PD4) were evaluated as endpoints. Healthy infants enrolled at 42-90 d after birth were vaccinated with V114 (N = 57). The most commonly reported AEs were those solicited in the trial. The majority of reported AEs were transient and of mild or moderate intensity. Few serious AEs were reported; none were vaccine related. No participants died nor discontinued the study vaccine because of an AE. V114 was immunogenic for all 15 serotypes contained in the vaccine, as assessed by IgG response rates at 30 d PD3 and IgG GMCs at 30 d PD3 and at 30 d PD4. V114 was well tolerated and immunogenic when administered as a 3 + 1 regimen in healthy South Korean infants and toddlers.

Cell-based therapeutic cancer vaccines use autologous patient-derived tumor cells, allogeneic cancer cell lines or autologous antigen presenting cells to mimic the natural immune process and stimulate an adaptive immune response against tumor antigens. The primary objective of this study is to perform a systematic literature review with an embedded meta-analysis of all published Phase 2 and 3 clinical trials of cell-based cancer vaccines in human subjects. The secondary objective of this study is to review trials demonstrating biological activity of cell-based cancer vaccines that could uncover additional hypotheses, which could be used in the design of future studies. We performed the systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The final review included 36 studies - 16 single-arm studies, and 20 controlled trials. Our systematic review of the existing literature revealed largely negative trials and our meta-analysis did not show evidence of clinical benefit from cell-based cancer-vaccines. However, as we looked beyond the stringent inclusion criteria of our systematic review, we identified significant examples of biological activity of cell-based cancer vaccines that are worth highlighting. In conclusion, the existing literature on cell-based cancer vaccines is highly variable in terms of cancer type, vaccine therapies and the clinical setting with no overall statistically significant clinical benefit, but there are individual successes that represent the promise of this approach. As cell-based vaccine technology continues to evolve, future studies can perhaps fulfill the potential that this exciting field of anti-cancer therapy holds.