A screening study on the detection strain of Coxsackievirus A6: the key to evaluating neutralizing antibodies in vaccines

The increasing incidence of diseases caused by Coxsackievirus A6 (CV-A6) and the presence of various mutants in the population present significant public health challenges. Given the concurrent development of multiple vaccines in China, it is challenging to objectively and accurately evaluate the level of neutralizing antibody response to different vaccines. The choice of the detection strain is a crucial factor that influences the detection of neutralizing antibodies. In this study, the National Institutes for Food and Drug Control collected a prototype strain (Gdula), one subgenotype D1, as well as 13 CV-A6 candidate vaccine strains and candidate detection strains (subgenotype D3) from various institutions and manufacturers involved in research and development. We evaluated cross-neutralization activity using plasma from naturally infected adults (n = 30) and serum from rats immunized with the aforementioned CV-A6 strains. Although there were differences between the geometric mean titer (GMT) ranges of human plasma and murine sera, the overall trends were similar. A significant effect of each strain on the neutralizing antibody test (MAX/MIN 48.0 ∼16410.3) was observed. Among all strains, neutralization of the S112 strain by 15 different sera resulted in higher neutralizing antibody titers (GMTS112 = 132.0) and more consistent responses across different genotypic immune sera (MAX/MIN = 48.0). Therefore, S112 may serve as a detection strain for NtAb testing in various vaccines, minimizing bias and making it suitable for evaluating the immunogenicity of the CV-A6 vaccine.

A modified recombinant adenovirus vector containing dual rabies virus G expression cassettes confers robust and long-lasting humoral immunity in mice, cats, and dogs

During the COVID-19 epidemic, the incidence of rabies has increased in several countries, especially in remote and disadvantaged areas, due to inadequate surveillance and declining immunization coverage. Multiple vaccinations with inactivated rabies virus vaccines for pre- or post-exposure prophylaxis are considered inefficient, expensive and impractical in developing countries. Herein, three modified human recombinant adenoviruses type 5 designated Adv-RVG, Adv-E1-RVG, and Adv-RVDG, carrying rabies virus G (RVG) expression cassettes in various combinations within E1 or E3 genomic regions, were constructed to serve as rabies vaccine candidates. Adv-RVDG mediated greater RVG expression both in vitro and in vivo and induced a more robust and durable humoral immune response than the rabies vaccine strain SAD-L16, Adv-RVG, and Adv-E1-RVG by more effectively activating the dendritic cells (DCs) - follicular helper T (Tfh) cells - germinal centre (GC) / memory B cells (MBCs) - long-lived plasma cells (LLPCs) axis with 100% survival after a lethal RABV challenge in mice during the 24-week study period. Similarly, dogs and cats immunized with Adv-RVDG showed stronger and longer-lasting antibody responses than those vaccinated with a commercial inactivated rabies vaccine and showed good tolerance to Adv-RVDG. In conclusion, our study demonstrated that simultaneous insertion of protective antigens into the E1 and E3 genomic regions of adenovirus vector can significantly enhance the immunogenicity of adenoviral-vectored vaccines, providing a theoretical and practical basis for the subsequent development of multivalent and multi-conjugated vaccines using recombinant adenovirus platform. Meanwhile, our data suggest Adv-RVDG is a safe, efficient, and economical vaccine for mass-coverage immunization.

A multistage Sendai virus vaccine incorporating latency-associated antigens induces protection against acute and latent tuberculosis

One-quarter of the world's population is infected with Mycobacterium tuberculosis (Mtb). After initial exposure, more immune-competent persons develop asymptomatic latent tuberculosis infection (LTBI) but not active diseases, creates an extensive reservoir at risk of developing active tuberculosis. Previously, we constructed a novel recombinant Sendai virus (SeV)-vectored vaccine encoding two dominant antigens of Mtb, which elicited immune protection against acute Mtb infection. In this study, nine Mtb latency-associated antigens were screened as potential supplementary vaccine candidate antigens, and three antigens (Rv2029c, Rv2028c, and Rv3126c) were selected based on their immune-therapeutic effect in mice, and their elevated immune responses in LTBI human populations. Then, a recombinant SeV-vectored vaccine, termed SeV986A, that expresses three latency-associated antigens and Ag85A was constructed. In murine models, the doses, titers, and inoculation sites of SeV986A were optimized, and its immunogenicity in BCG-primed and BCG-naive mice were determined. Enhanced immune protection against the Mtb challenge was shown in both acute-infection and latent-infection murine models. The expression levels of several T-cell exhaustion markers were significantly lower in the SeV986A-vaccinated group, suggesting that the expression of latency-associated antigens inhibited the T-cell exhaustion process in LTBI infection. Hence, the multistage quarter-antigenic SeV986A vaccine holds considerable promise as a novel post-exposure prophylaxis vaccine against tuberculosis.

Dynamic Covalent Hydrogel as a Single-dose Vaccine Adjuvant for Sustained Antigen Release and Significantly Elevated Humoral Immunity

Vaccine is the most important way for fighting against infection diseases. However, multiple injections and unsatisfied immune responses are the main obstacles for current vaccine application. Herein, a dynamic covalent hydrogel (DCH) was used as a single-dose vaccine adjuvant for eliciting robust and sustained humoral immunity. By adjusting the mass ratio of the DCH gel, we successfully realized 10 to 30 days constant release of the loaded recombinant protein antigens, and proved that sustained release of antigens could significantly improve the vaccine efficacy. When loading SARS-CoV-2 RBD (Wuhan and Omicron BA.1 strains) antigens into this DCH gel, an over 32,000 times and 8,000 times improvement was observed in antigen-specific antibody titers compared to conventional Aluminum adjuvanted vaccines. The universality of this DCH gel adjuvant was confirmed in a Nipah G antigen test as well as a H1N1 influenza virus antigen test, with much improved protection of C57BL/6 mice against H1N1 virus infection than conventional Aluminum adjuvanted vaccines. This sustainably released, single-dose DCH gel adjuvant provides a new promising option for designing next-generation infection vaccines. This article is protected by copyright. All rights reserved.

Omicron neutralization character in patients with breast cancer and liver cancer after the nationwide omicron outbreak

BACKGROUND

The surge in omicron variants has caused nationwide breakthrough infections in mainland China since the December 2022. In this study, we report the neutralization profiles of serum samples from the patients with breast cancer and the patients with liver cancer who had contracted subvariant breakthrough infections.

METHODS

In this real-world study, we enrolled 143 COVID-19-vaccinated (81 and 62 patients with breast and liver cancers) and 105 unvaccinated patients with cancer (58 and 47 patients with breast and liver cancers) after omicron infection. Anti-spike receptor binding domain (RBD) IgGs and 50% pseudovirus neutralization titer (pVNT50) for the preceding (wild type), circulating omicron (BA.4-BA.5, and BF.7), and new subvariants (XBB.1.5) were comprehensively analyzed.

RESULTS

Patients with liver cancer receiving booster doses had higher levels of anti-spike RBD IgG against circulating omicron (BA.4-BA.5, and BF.7) and a novel subvariant (XBB.1.5) compared to patients with breast cancer after breakthrough infection. Additionally, all vaccinated patients produced higher neutralizing antibody titers against circulating omicron (BA.4-BA.5, and BF.7) compared to unvaccinated patients. However, the unvaccinated patients produced higher neutralizing antibody against XBB.1.5 than vaccinated patients after Omicron infection, with this trend being more pronounced in breast cancer than in liver cancer patients. Moreover, we found that there was no correlation between anti-spike RBD IgG against wildtype virus and the neutralizing antibody titer, but a positive correlation between anti-spike RBD IgG and the neutralizing antibody against XBB.1.5 was found in unvaccinated patients.

CONCLUSION

Our study found that there may be differences in vaccine response and protective effect against COVID-19 infection in patients with liver and breast cancer. Therefore, we recommend that COVID-19 vaccine strategies should be optimized based on vaccine components and immunology profiles of different patients with cancer.

Self-Reported Olfactory and Gustatory Dysfunctions in Hospitalized Patients Infected with SARS-CoV-2 Delta Variant

OBJECTIVE

This study aimed to examine the olfactory and gustatory dysfunctions (OGDs) among hospitalized patients with a novel strain of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), lineage B.1.617.2, also known as the delta variant, in Xi'an, China through verbal interviews.

METHODS

Clinical information of 370 hospitalized patients infected with the delta variant in the Aerospace City Branch of Xi'an People's Hospital in Xi'an, China from December 27, 2021 to January 10, 2022 were collected. The prevalence and characteristics of OGDs were collected using a simple questionnaire submitted to all infected patients, including questions about the presence and absence of OGDs.

RESULTS

Among the 370 patients infected with the delta variant, 28 (7.6%) reported OGDs. A significant proportion of patients with self-reported OGDs were younger than those without (28.9 ± 10.5 vs. 35.3 ± 13.9, P = 0.005) and had significantly higher rates of sore throat and rhinitis (28.6% vs. 12.3%, P = 0.033; 42.9% vs. 9.9%, P = 0.000). Women were significantly more affected by OGDs than men (67.9% vs. 32.1%, P = 0.012). Vaccinated and unvaccinated delta variant-infected patients showed statistically significant differences in terms of disease severity (P = 0.002).

CONCLUSIONS

The prevalence of OGDs in the delta variant infection was lower than that in wild-type SARS-CoV-2 infection. Meanwhile, young age, female sex, and upper respiratory tract symptoms could be closely related to the occurrence of OGDs in the delta variant infection. In addition, a satisfactory level of efficacy was obtained with coronavirus disease 2019 vaccines against moderate and severe delta variant infections.

A Case Report of Sudden Sensorineural Hearing Loss (SSNHL) After Administration of the COVID-19 Vaccine

Since the issuance of the emergency use authorization (EUA) of 3 coronavirus disease 2019 (COVID-19) vaccines, there have been over 180 million individuals fully vaccinated in the United States (US). With the increasing administration of COVID-19 vaccinations, there have been over 550,000 adverse events reported in the Vaccine Adverse Event Reporting System (VAERS) with approximately 230,000 experienced after receipt of the Pfizer-BioNTech COVID-19 Vaccine as of September 23rd 2021. Audio-vestibular symptoms (including Sudden Sensorineural Hearing Loss (SSNHL)) secondary to immunizations has previously been evaluated. However, this report describes the first case of bilateral sudden sensorineural hearing loss potentially due to the Pfizer-BioNTech COVID-19 vaccine. We further review the available literature regarding the treatment of Sudden Sensorineural Hearing Loss, and the association of SSNHL with previous immunizations and COVID-19 infection. Lastly, we hypothesize the underlying potential mechanisms between SSNHL and the Pfizer-BioNTech COVID-19 vaccine.

Circadian Variation in the Response to Vaccination: A Systematic Review and Evidence Appraisal

Molecular timing mechanisms known as circadian clocks drive endogenous 24-h rhythmicity in most physiological functions, including innate and adaptive immunity. Consequently, the response to immune challenge such as vaccination might depend on the time of day of exposure. This study assessed whether the time of day of vaccination (TODV) is associated with the subsequent immune and clinical response by conducting a systematic review of previous studies. The Cochrane Library, PubMed, Google, Medline, and Embase were searched for studies that reported TODV and immune and clinical outcomes, yielding 3114 studies, 23 of which met the inclusion criteria. The global severe acute respiratory syndrome coronavirus 2 vaccination program facilitated investigation of TODV and almost half of the studies included reported data collected during the COVID-19 pandemic. There was considerable heterogeneity in the demography of participants and type of vaccine, and most studies were biased by failure to account for immune status prior to vaccination, self-selection of vaccination time, or confounding factors such as sleep, chronotype, and shiftwork. The optimum TODV was concluded to be afternoon (5 studies), morning (5 studies), morning and afternoon (1 study), midday (1 study), and morning or late afternoon (1 study), with the remaining 10 studies reporting no effect. Further research is required to understand the relationship between TODV and subsequent immune outcome and whether any clinical benefit outweighs the potential effect of this intervention on vaccine uptake.

The immune response of pregnant sow after vaccination with crude fimbriae (F4) extracts vaccine and immunoprotection of nursery pig against pathogenic E. coli (F4+ETEC)

BACKGROUND

Neonatal and post-weaning diarrhea is a concern disease caused by enterotoxigenic Escherichia coli fimbriae F4 (F4+ETEC) in pig farms. Diarrhea outbreaks are often severe and costly due to the high prevalence and spread of the disease within the same herd. Vaccine is one of strategic solution in protecting pig against F4+ETEC infection in particular pig farm. In present study, we conducted two trials of vaccination with crude F4 fimbriae extract vaccine in pregnant sow and nursery pigs.

METHODS

In experiment 1 (20 sows; non-vaccinated control, n=10), we vaccinated pregnant sows (n=10) twice at 4 wk and 2 wk before farrowing and evaluated impact of vaccination on maternal immunity. The sow serum and colostrum were collected before vaccination, 2 and 4 weeks after vaccination, 6 hours after farrowing, respectively, and the piglet's serum from both groups (2 piglet/sow, 10 piglets from each group) were also collected on 3 days old to measure F4 specific IgG, F4 specific IgA using in house ELISA kit. In experiment 2, to optimize doses and dosage of candidate vaccine in piglets, 18 piglets (3 piglets/group) were allocated into five immunized groups and one control group (unimmunized group), we immunized piglets twice at 4 and 6 weeks old with difference doses (i.e., 0, 50, 100, 150, 200 µg), and for a dose 150 µg, we immunized with two dosages at 1 ml and 2 ml. Piglets were challenged with a 3 ml dose of 3 × 109 CFU/ml bacterial culture of enterotoxigenic Escherichia coli (F4+ETEC) in order to evaluate the efficacy of vaccine. After challenging, the clinical sign of the piglets was daily observed and the rectal swab was performed every day for investigation of the fecal shedding of Escherichia coli (F4+ETEC) by using PCR technique. Serum were collected before, 2 and 4 weeks after vaccination and 1 week after challenge to measure F4 specific IgG, F4 specific IgA using in house ELISA kit and cytokines levels (i.e., IL-1 beta, IL-6, IL-8 and TNF alpha) before and 1 week after challenge using commercial ELISA kit.

RESULTS

The levels of antibody results showed that in experiment 1, the anti-F4 antibody levels both F4 specific IgG and F4 specific IgA in serum and colostrum of vaccinated sow increased significantly after vaccination. The piglets of immunized sows have antibody level both F4 specific IgG and F4 specific IgA in their serum higher than those piglets of unimmunized sows significantly (p < 0.01). In experiment 2, irrespective of different doses and dosage, there is no difference in term of F4 specific IgG and F4 specific IgA levels among immunized groups. However, all of vaccinated piglets showed F4 specific IgG and F4 specific IgA levels higher and the elimination of Escherichia coli (F4+ETEC) in feces post challenge faster (< 3 days) than unvaccinated group (> 5 days). For cytokines levels, a higher level of IL-1 beta, IL-6, IL-8 and TNF alpha at 1 week after challenge in vaccinated groups was found when compared with the levels in non-vaccinated group.

CONCLUSIONS

Our results suggest that crude F4 fimbriae extract autogenous vaccine is a candidate vaccine for protecting piglets against diarrhea disease caused by enterotoxigenic Escherichia coli (F4+ETEC) and vaccination the pregnant sow twice before farrowing is one of strategies to provide maternal derived antibody to the newborn piglets for against enterotoxigenic Escherichia coli (F4+ETEC) during early life.

Global and regional burden of vaccine-associated facial paralysis, 1967-2023: Findings from the WHO international pharmacovigilance database

The scarce and conflicting data on vaccine-associated facial paralysis limit our understanding of vaccine safety on a global scale. Therefore, this study aims to evaluate the global burden of vaccine-associated facial paralysis and to identify the extent of its association with individual vaccines, thereby contributing to the development of a more effective vaccination program. We used data on vaccine-associated facial paralysis from 1967 to 2023 (total reports, n = 131 255 418 418) from the World Health Organization International Pharmacovigilance Database. Global reporting counts, reported odds ratios (ROR), and information components (ICs) were computed to elucidate the association between the 16 vaccines and the occurrence of vaccine-associated facial paralysis across 156 countries. We identified 26 197 reports (men, n = 10 507 [40.11%]) of vaccine-associated facial paralysis from 49 537 reports of all-cause facial paralysis. Vaccine-associated facial paralysis has been consistently reported; however, a pronounced increase in reported incidence has emerged after the onset of the coronavirus disease 2019 (COVID-19) pandemic, which is attributable to the COVID-19 mRNA vaccine. Most vaccines were associated with facial paralysis, with differing levels of association, except for tuberculosis vaccines. COVID-19 mRNA vaccines had the highest association with facial paralysis reports (ROR, 28.31 [95% confidence interval, 27.60-29.03]; IC, 3.37 [IC0.25, 3.35]), followed by encephalitis, influenza, hepatitis A, papillomavirus, hepatitis B, typhoid, varicella-zoster, meningococcal, Ad-5 vectored COVID-19, measles, mumps and rubella, diphtheria, tetanus toxoids, pertussis, polio, and Hemophilus influenza type b, pneumococcal, rotavirus diarrhea, and inactivated whole-virus COVID-19 vaccines. Concerning age- and sex-specific risks, vaccine-associated facial paralysis was more strongly associated with older age groups and males. The serious adverse outcome and death rate of vaccine-associated facial paralysis were extremely low (0.07% and 0.00%, respectively). An increase in vaccine-induced facial paralysis, primarily owing to COVID-19 mRNA vaccines, was observed with most vaccines, except tuberculosis vaccines. Given the higher association observed in the older and male groups with vaccine-associated facial paralysis, close monitoring of these demographics when administering vaccines that are significantly associated with adverse reactions is crucial.

Vaccine Targeting Alpha 1D-Adrenergic Receptor Improved Metabolic Syndrome in Mice

PURPOSE

Metabolic syndrome (MetS) is a complex chronic disease that includes obesity and hypertension, with rising evidence demonstrating that sympathetic nervous system (SNS) activation plays a key role. Our team designed a therapeutic vaccine called ADRQβ-004 targeting the α1D-adrenergic receptor (α1D-AR). This study was performed to investigate whether the ADRQβ-004 vaccine improves MetS by modulating SNS activity.

METHODS

C57BL/6N mice were fed a high-fat diet (HFD) and Nω-nitro-L-arginine methyl ester (L-NAME) combination diet for 18 weeks to elicit MetS. The MetS mice were subcutaneously immunized with the ADRQβ-004 vaccine four times to evaluate the therapeutic efficacy in obesity and hypertension and other associated abnormalities related to MetS by conducting echocardiographic, histological, and biochemical analyses.

RESULTS

The ADRQβ-004 vaccine induced strong antibody production and maintained a high anti-ADR-004 antibody titer in MetS mice. The ADRQβ-004 vaccine improved obesity (P < 0.001) and decreased systolic blood pressure (P < 0.001). Improvements in dysregulated glucose homeostasis and dyslipidemia resulting from the ADRQβ-004 vaccine were also confirmed. Furthermore, the ADRQβ-004 vaccine attenuated cardiovascular functional (P = 0.015) and structural changes (P < 0.001), decreased fat accumulation (P = 0.012) and inflammation (P = 0.050) in the epididymal white adipose tissue, and alleviated hepatic steatosis (P = 0.043) involved in MetS. Moreover, the ADRQβ-004 vaccine improved systematic and visceral organs SNS activities in the MetS.

CONCLUSION

This study demonstrated for the first time that the ADRQβ-004 vaccine targeting α1D-AR improved obesity, hypertension, dyslipidemia, and dysglycemia, and further reduced end-organ damage, which may provide new motivation for MetS research.

The Effectiveness of Vaccination on the COVID-19 Epidemic in California

BACKGROUND

The COVID-19 pandemic has caused overwhelming morbidity, mortality, and hospitalization worldwide, including in the state of California. Vaccination efforts have been an important measure in curtailing the adverse outcomes of COVID-19.

METHODS

To quantify the effectiveness of COVID-19 vaccinations in California, we conducted a retrospective cohort study investigating how vaccination has impacted the extent of COVID-19 contraction, hospitalizations, and death totals. We compared outcomes the Delta Wave, Omicron Wave, and Pre-Delta Period.

RESULTS

Vaccinated individuals have far lower incidence risk ratio (IRR) of and odds of contracting a COVID-19 case (Delta IRR: 0.197) being hospitalized from COVID-19 (Delta IRR: 0.105]), and dying from COVID-19 compared to an unvaccinated individual (Delta IRR: 0.0941). The preventive fraction of the unexposed and population preventive fractions for cases, deaths, and hospitalizations also showed significant proportions. All tests showed p<0.001.

DISCUSSION

Vaccination was most effective in the Delta Wave, then in the Omicron Wave, and least effective in the Pre-Delta Period. Deaths were the most prevented outcome, followed by hospitalizations, then cases.

CONCLUSION

This study exposes the massive impact of vaccinations in California in reducing COVID-19 outcomes and the potential for fewer adverse outcomes had there been greater vaccination compliance, demonstrating the need to increase vaccination efforts.

CONTENT CATEGORY

Epidemiology.

Urgent Need to Understand and Prevent Gonococcal Infection: From the Laboratory to Real-World Context

Neisseria gonorrhoeae is widespread globally. Primary prevention is unsuccessful and antimicrobial resistance threatens optimal management. There is no specific vaccine and natural infection studies show that N. gonorrhoeae can avoid and suppress immune responses. In addition to extensive variation in expression and specificity of many gonococcal surface antigens, it induces a robust inflammatory response through the Th17 pathway with a large influx of neutrophils and inflammatory cytokines but evades macrophages. The Th1- and Th2-mediated response is suppressed, resulting in low, short-lived antibody titers. Real-world evidence suggests that gonorrhea cases are reduced among recipients of N. meningitidis group B vaccines containing outer membrane vesicles (OMV). Although the first randomized trial of an OMV-containing MenB vaccine against N. gonorrhoeae infection did not show statistically significant vaccine efficacy, ongoing trials might shed further light. Several candidate vaccine antigens for a gonococcal-specific vaccine are being evaluated preclinically but only one has reached clinical trials.

Cholesterol reduction by immunization with a PCSK9 mimic

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a plasma protein that controls cholesterol homeostasis. Here, we design a human PCSK9 mimic, named HIT01, with no consecutive 9-residue stretch in common with any human protein as a potential heart attack vaccine. Murine immunizations with HIT01 reduce low-density lipoprotein (LDL) and cholesterol levels by 40% and 30%, respectively. Immunization of cynomolgus macaques with HIT01-K21Q-R218E, a cleavage-resistant variant, elicits high-titer PCSK9-directed antibody responses and significantly reduces serum levels of cholesterol 2 weeks after each immunization. However, HIT01-K21Q-R218E immunizations also increase serum PCSK9 levels by up to 5-fold, likely due to PCSK9-binding antibodies altering the half-life of PCSK9. While vaccination with a PCSK9 mimic can induce antibodies that block interactions of PCSK9 with the LDL receptor, PCSK9-binding antibodies appear to alter homeostatic levels of PCSK9, thereby confounding its vaccine impact. Our results nevertheless suggest a mechanism for increasing the half-life of soluble regulatory factors by vaccination.

Unveiling the immune dynamics of Neisseria persistent oral colonization

Commensal bacteria are crucial in maintaining host physiological homeostasis, immune system development, and protection against pathogens. Despite their significance, the factors influencing persistent bacterial colonization and their impact on the host still need to be fully understood. Animal models have served as valuable tools to investigate these interactions, but most have limitations. The bacterial genus Neisseria, which includes both commensal and pathogenic species, has been studied from a pathogenicity to humans perspective but lacks models that study immune responses in the context of long-term persistence. Neisseria musculi, a recently described natural commensal of mice, offers a unique opportunity to study long-term host-commensal interactions. In this study, for the first time, we have used this model to study the transcriptional, phenotypic, and functional dynamics of immune cell signatures in the mucosal and systemic tissue of mice in response to N. musculi colonization. We found key genes and pathways vital for immune homeostasis in palate tissue, validated by flow cytometry of immune cells from the lung, blood, and spleen. This study offers a novel avenue for advancing our understanding of host-bacteria dynamics and may provide a platform for developing efficacious interventions against mucosal persistence by pathogenic Neisseria.

A targeted single mutation in influenza A virus universal epitope transforms immunogenicity and protective immunity via CD4+ T cell activation

CD4+ T cells are central to adaptive immunity. Their role in cross-protection in viral infections such as influenza and severe acute respiratory syndrome (SARS) is well documented; however, molecular rules governing T cell receptor (TCR) engagement of peptide-human leukocyte antigen (pHLA) class II are less understood. Here, we exploit an aspect of HLA class II presentation, the peptide-flanking residues (PFRs), to "tune" CD4+ T cell responses within an in vivo model system of influenza. Using a recombinant virus containing targeted substitutions at immunodominant HLA-DR1 epitopes, we demonstrate limited weight loss and improved clinical scores after heterosubtypic re-challenge. We observe enhanced protection linked to lung-derived influenza-specific CD4+ and CD8+ T cells prior to re-infection. Structural analysis of the ternary TCR:pHLA complex identifies that flanking amino acids influence side chains in the core 9-mer peptide, increasing TCR affinity. Augmentation of CD4+ T cell immunity is achievable with a single mutation, representing a strategy to enhance adaptive immunity that is decoupled from vaccine modality.

Campylobacteriosis and Control Strategies against Campylobacters in Poultry Farms

Campylobacteriosis is a significant foodborne illness caused by Campylobacter bacteria. It is one of the most common bacterial causes of gastroenteritis worldwide, with poultry being a major reservoir and source of infection in humans. In poultry farms, Campylobacters colonize the intestinal tract of chickens and contaminate meat during processing. Vaccines under development against Campylobacters in poultry showed partial or no protection against their cecal colonization. Therefore, this review will elaborate on campylobacteriosis and emphasize the control strategies and recent vaccine trials against Campylobacters in poultry farms. The epidemiology, diagnosis, and treatment of Campylobacter infection, along with specific mention of poultry Campylobacter contamination events in Malaysia, will also be discussed.

Stabilized trimeric peptide immunogens of the complete HIV-1 gp41 N-heptad repeat and their use as HIV-1 vaccine candidates

Efforts to develop an HIV-1 vaccine include those focusing on conserved structural elements as the target of broadly neutralizing monoclonal antibodies. MAb D5 binds to a highly conserved hydrophobic pocket on the gp41 N-heptad repeat (NHR) coiled coil and neutralizes through prevention of viral fusion and entry. Assessment of 17-mer and 36-mer NHR peptides presenting the D5 epitope in rodent immunogenicity studies showed that the longer peptide elicited higher titers of neutralizing antibodies, suggesting that neutralizing epitopes outside of the D5 pocket may exist. Although the magnitude and breadth of neutralization elicited by NHR-targeting antigens are lower than that observed for antibodies directed to other epitopes on the envelope glycoprotein complex, it has been shown that NHR-directed antibodies are potentiated in TZM-bl cells containing the FcγRI receptor. Herein, we report the design and evaluation of covalently stabilized trimeric 51-mer peptides encompassing the complete gp41 NHR. We demonstrate that these peptide trimers function as effective antiviral entry inhibitors and retain the ability to present the D5 epitope. We further demonstrate in rodent and nonhuman primate immunization studies that our 51-mer constructs elicit a broader repertoire of neutralizing antibody and improved cross-clade neutralization of primary HIV-1 isolates relative to 17-mer and 36-mer NHR peptides in A3R5 and FcγR1-enhanced TZM-bl assays. These results demonstrate that sensitive neutralization assays can be used for structural enhancement of moderately potent neutralizing epitopes. Finally, we present expanded trimeric peptide designs which include unique low-molecular-weight scaffolds that provide versatility in our immunogen presentation strategy.

Vaccination status among children in an urban area and its association with risk factors and some parent health practices: A cross-sectional study

OBJECTIVE

The study aims to determine the vaccination status of children and evaluate the relationship between vaccination rates, vaccine attitudes, and some parental health practices.

DESIGN AND METHODS

This cross-sectional study was conducted with 674 mothers. Data were collected using a survey evaluating vaccine characteristics, some infant health practices, and The Public Attitude Toward Vaccination Scale-Health Belief Model. Chi-square test, independent samples t-test, and logistic regression analysis were used.

RESULTS

80.2% of children were fully vaccinated. The rate of non or under-vaccination was higher in the group that did not regularly undergo follow-up for 0-2-year-old children, did not fully have health screenings, did not use vitamin D and iron supplements, and used alternative medicine. Moreover, the duration of breast milk feeding, the transition to supplementary food, and the duration of vitamin D use in the non-fully vaccinated group were lower than in the fully vaccinated group (p < .05). The increase in maternal education period and severity and benefit attitude scores of vaccine attitude were the factors that decreased the rate of non-fully vaccination. The increase in barrier scores toward vaccines increased the rate of non or under-vaccination.

CONCLUSION

Mothers who have negative attitudes toward vaccination have negative behaviors in health practices and screenings on infant/child health.

Development of Next-Generation COVID-19 Vaccines: BARDA Supported Phase 2b Study Designs

In response to the COVID-19 pandemic, vaccines were quickly and successfully developed and deployed, saving millions of lives globally. While first generation vaccines are safe and effective in preventing disease caused by SARSCoV-2, next-generation vaccines have the potential to improve efficacy and safety. Vaccines delivered by a mucosal route may elicit greater protective immunity at respiratory surfaces thereby reducing transmission. Inclusion of viral antigens in addition to the spike protein may enhance protection against emerging variants of concern. Next-generation vaccine platforms with a new mechanism of action may necessitate efficacy trials to fulfill regulatory requirements. The Biomedical Advanced Research and Development Authority (BARDA) will be supporting Phase 2b clinical trials of candidate next-generation vaccines. The primary endpoint will be improved efficacy in terms of symptomatic disease relative to a currently approved COVID-19 vaccine. In this paper, we discuss the planned endpoints and potential challenges to this complex program.

SARS-CoV-2 vaccination in the first year after hematopoietic cell transplant or chimeric antigen receptor T cell therapy: A prospective, multicenter, observational study

BACKGROUND

The optimal timing of vaccination with SARS-CoV-2 vaccines after cellular therapy is incompletely understood. The objectives of this study are to determine whether humoral and cellular responses after SARS-CoV-2 vaccination differ if initiated <4 months versus 4-12 months after cellular therapy.

METHODS

We conducted a multicenter prospective observational study at 30 cancer centers in the United States. SARS-CoV-2 vaccination was administered as part of routine care. We obtained blood prior to and after vaccinations at up to five time points and tested for SARS-CoV-2 spike (anti-S) IgG in all participants and neutralizing antibodies for Wuhan D614G, Delta B.1.617.2, and Omicron B.1.1.529 strains, as well as SARS-CoV-2-specific T cell receptors (TCRs), in a subgroup.

RESULTS

We enrolled 466 allogeneic hematopoietic cell transplant (HCT; n=231), autologous HCT (n=170), and chimeric antigen receptor T cell (CAR-T cell) therapy (n=65) recipients between April 2021 and June 2022. Humoral and cellular responses did not significantly differ among participants initiating vaccinations <4 months vs 4-12 months after cellular therapy. Anti-S IgG ≥2,500 U/mL was correlated with high neutralizing antibody titers and attained by the last time point in 70%, 69%, and 34% of allogeneic HCT, autologous HCT, and CAR-T cell recipients, respectively. SARS-CoV-2-specific T cell responses were attained in 57%, 83%, and 58%, respectively. Pre-cellular therapy SARS-CoV-2 infection or vaccination were key predictors of post-cellular therapy immunity.

CONCLUSIONS

These data support mRNA SARS-CoV-2 vaccination prior to, and reinitiation three to four months after, cellular therapies with allogeneic HCT, autologous HCT, and CAR-T cell therapy.

A Profile of Influenza Vaccine Coverage for 2019-2020: Database Study of the English Primary Care Sentinel Cohort

BACKGROUND

Innovation in seasonal influenza vaccine development has resulted in a wider range of formulations becoming available. Understanding vaccine coverage across populations including the timing of administration is important when evaluating vaccine benefits and risks.

OBJECTIVE

This study aims to report the representativeness, uptake of influenza vaccines, different formulations of influenza vaccines, and timing of administration within the English Primary Care Sentinel Cohort (PCSC).

METHODS

We used the PCSC of the Oxford-Royal College of General Practitioners Research and Surveillance Centre. We included patients of all ages registered with PCSC member general practices, reporting influenza vaccine coverage between September 1, 2019, and January 29, 2020. We identified influenza vaccination recipients and characterized them by age, clinical risk groups, and vaccine type. We reported the date of influenza vaccination within the PCSC by International Standard Organization (ISO) week. The representativeness of the PCSC population was compared with population data provided by the Office for National Statistics. PCSC influenza vaccine coverage was compared with published UK Health Security Agency's national data. We used paired t tests to compare populations, reported with 95% CI.

RESULTS

The PCSC comprised 7,010,627 people from 693 general practices. The study population included a greater proportion of people aged 18-49 years (2,982,390/7,010,627, 42.5%; 95% CI 42.5%-42.6%) compared with the Office for National Statistics 2019 midyear population estimates (23,219,730/56,286,961, 41.3%; 95% CI 4.12%-41.3%; P<.001). People who are more deprived were underrepresented and those in the least deprived quintile were overrepresented. Within the study population, 24.7% (1,731,062/7,010,627; 95% CI 24.7%-24.7%) of people of all ages received an influenza vaccine compared with 24.2% (14,468,665/59,764,928; 95% CI 24.2%-24.2%; P<.001) in national data. The highest coverage was in people aged ≥65 years (913,695/1,264,700, 72.3%; 95% CI 72.2%-72.3%). The proportion of people in risk groups who received an influenza vaccine was also higher; for example, 69.8% (284,280/407,228; 95% CI 69.7%-70%) of people with diabetes in the PCSC received an influenza vaccine compared with 61.2% (983,727/1,607,996; 95% CI 61.1%-61.3%; P<.001) in national data. In the PCSC, vaccine type and brand information were available for 71.8% (358,365/498,923; 95% CI 71.7%-72%) of people aged 16-64 years and 81.9% (748,312/913,695; 95% CI 81.8%-82%) of people aged ≥65 years, compared with 23.6% (696,880/2,900,000) and 17.8% (1,385,888/7,700,000), respectively, of the same age groups in national data. Vaccination commenced during ISO week 35, continued until ISO week 3, and peaked during ISO week 41. The in-week peak in vaccination administration was on Saturdays.

CONCLUSIONS

The PCSC's sociodemographic profile was similar to the national population and captured more data about risk groups, vaccine brands, and batches. This may reflect higher data quality. Its capabilities included reporting precise dates of administration. The PCSC is suitable for undertaking studies of influenza vaccine coverage.

Structural basis for the broad antigenicity of the computationally optimized influenza hemagglutinin X6

Influenza causes significant morbidity and mortality. As an alternative approach to current seasonal vaccines, the computationally optimized broadly reactive antigen (COBRA) platform has been previously applied to hemagglutinin (HA). This approach integrates wild-type HA sequences into a single immunogen to expand the breadth of accessible antibody epitopes. Adding to previous studies of H1, H3, and H5 COBRA HAs, we define the structural features of another H1 subtype COBRA, X6, that incorporates HA sequences from before and after the 2009 H1N1 influenza pandemic. We determined structures of this antigen alone and in complex with COBRA-specific as well as broadly reactive and functional antibodies, analyzing its antigenicity. We found that X6 possesses features representing both historic and recent H1 HA strains, enabling binding to both head- and stem-reactive antibodies. Overall, these data confirm the integrity of broadly reactive antibody epitopes of X6 and contribute to design efforts for a next-generation vaccine.

Dose escalation study of a personalized peptide-based neoantigen vaccine (EVX-01) in patients with metastatic melanoma

BACKGROUND

Neoantigens can serve as targets for T cell-mediated antitumor immunity via personalized neopeptide vaccines. Interim data from our clinical study NCT03715985 showed that the personalized peptide-based neoantigen vaccine EVX-01, formulated in the liposomal adjuvant, CAF09b, was safe and able to elicit EVX-01-specific T cell responses in patients with metastatic melanoma. Here, we present results from the dose-escalation part of the study, evaluating the feasibility, safety, efficacy, and immunogenicity of EVX-01 in addition to anti-PD-1 therapy.

METHODS

Patients with metastatic melanoma on anti-PD-1 therapy were treated in three cohorts with increasing vaccine dosages (twofold and fourfold). Tumor-derived neoantigens were selected by the AI platform PIONEER and used in personalized therapeutic cancer peptide vaccines EVX-01. Vaccines were administered at 2-week intervals for a total of three intraperitoneal and three intramuscular injections. The study's primary endpoint was safety and tolerability. Additional endpoints were immunological responses, survival, and objective response rates.

RESULTS

Compared with the base dose level previously reported, no new vaccine-related serious adverse events were observed during dose escalation of EVX-01 in combination with an anti-PD-1 agent given according to local guidelines. Two patients at the third dose level (fourfold dose) developed grade 3 toxicity, most likely related to pembrolizumab. Overall, 8 out of the 12 patients had objective clinical responses (6 partial response (PR) and 2 CR), with all 4 patients at the highest dose level having a CR (1 CR, 3 PR). EVX-01 induced peptide-specific CD4+ and/or CD8+T cell responses in all treated patients, with CD4+T cells as the dominating responses. The magnitude of immune responses measured by IFN-γ ELISpot assay correlated with individual peptide doses. A significant correlation between the PIONEER quality score and induced T cell immunogenicity was detected, while better CRs correlated with both the number of immunogenic EVX-01 peptides and the PIONEER quality score.

CONCLUSION

Immunization with EVX-01-CAF09b in addition to anti-PD-1 therapy was shown to be safe and well tolerated and elicit vaccine neoantigen-specific CD4+and CD8+ T cell responses at all dose levels. In addition, objective tumor responses were observed in 67% of patients. The results encourage further assessment of the antitumor efficacy of EVX-01 in combination with anti-PD-1 therapy.

Knowledge, Attitudes, and Practice towards Rabies in Gharbia Gover-norate, Egypt: A Cross-Sectional Study

BACKGROUND

Rabies is a fatal infectious viral disease that affects all warm-blooded mammals, including humans. Rabid dogs are commonly found in Egypt.

AIMS

By assessing the knowledge, attitudes, and practices towards Rabies in Gharbia Governorate, Egypt, this KAP study aimed to improve knowledge of the populations dealing with infected wounds and rabid animals. It also aimed to generate baseline data that would be a reference for evaluating community awareness and aid in developing and administering appropriate rabies prevention strategies.

METHODS

This is a cross-sectional study that was carried out from June 2020 to October 2022 to assess the knowledge, attitudes, and practices of six different towns and villages from the El Gharbia government, Egypt, regarding rabies. A self-administered closed-ended questionnaire was used to collect the data from 326 participants by convenient sampling. The data were analyzed by SPSS statistical software version 21 using descriptive analysis and the Chi-square test.

RESULTS

Most of the respondents (73.6%) had heard about rabies mainly from mixed sources (formal and informal sources). The bite was considered to be the only mode of transmission of rabies by 49.4% of respondents, and only 10.7% and 14.4% of respondents answered that it could be transmitted by scratching and saliva contact, respectively. Nearly half of the participants (52.1%) believed that biting and sudden changes in behavior are the clinical signs and symptoms of rabies in humans. Most of the participants (70.9 %) knew that rabies could be prevented by vaccination, but (57.1%) of them did not know about the almost 100% fatal nature of rabies once the clinical signs developed. Residency, educational status, and age were found to be significantly associated with KAP of rabies (P<0.05).

CONCLUSION

There is a need for educational campaigns and mass media programs in the El Ghar-bia government, Egypt to increase the awareness of the community about rabies.