Vaccine Response Research Articles

Vaccinations in older adults: Optimization, strategies, and latest guidelines.

This article is a summary of the first AGS Symposium entitled "Update on Vaccination Strategies for Older Adults: Matching the Approach to the Individual and the Care Setting." Given declines in host defenses and immune function with aging, vaccinations play a pivotal role in fortifying older adults against preventable infections, resulting diseases, disability, and death. Current guidelines generally list recommendations applicable for an average older adult of a given chronological age. However, growing evidence indicates that heterogeneity in terms of factors as varied as biological sex, frailty, functional status, and multimorbidity may impact vaccine responses and clinical outcomes. As a result, clinicians will increasingly need to take these additional factors into consideration as they seek to improve outcomes through improved targeting of such aging-related heterogeneity. Moreover, efforts at protecting older citizens through vaccination must also include strategies to overcome barriers to the adoption of vaccine recommendations in varied settings including long-term care. This 2023 AGS Plenary Symposium sought to commence a broader dialogue across AGS and beyond on optimizing vaccinations for older adults, ensuring not only extended lifespans but also healthier and more active lives. This report is not a systematic review, and thus should not be considered comprehensive.

Sex-specific immune responses to COVID-19 vaccination in end-stage renal disease patients

Abstract Background End-stage renal disease (ESRD) patients have muted memory B cell formation and reduced humoral responses to COVID-19 vaccination; however, early innate immune responses have yet to be characterized. Sex-stratification is also limited in COVID-19 vaccination research. Methods We collected blood before (BD1) and 1-4 days post-dose 1 (PD1) of BNT162b2 vaccination for RNA-sequencing in ESRD patients (n = 35 BD1; 18 PD1) and healthy controls (HC) (n = 31 BD1; 30 PD1). Additionally, 20 plasma cytokines were quantified in ESRD patients (n = 39 BD1, 35 PD1) and HC (34 BD1, 15 PD1). Results Transcriptional profiling of vaccine responses identified 125 significantly differentially expressed genes (DEG) (padj<0.04) in ESRD patients and 107 DEGs (padj<0.05) in HC. 71 DEGs were shared, 54 unique to ESRD, and 36 unique to HC. DEG, pathway analyses, and cytokine responses in the combined dataset showed ESRD patients were more inflamed than HC at baseline, with an elevated inflammatory cytokine profile compared to HC. These results were driven by female ESRD patients where IL-2, IL-10, and IP-10 were more significant in females (p < 0.001) compared to males (p < 0.01). While IL-6, IFN-γ, IL-13, eotaxin, were exclusively associated in females (p < 0.05). Healthy females also had a stronger immunological response to vaccination compared to healthy males. Conclusions Despite baseline inflammation, ESRD patients were able to mount similar early immune responses to vaccination as HC, with females in both populations more reactogenic than males. Sex-stratification is recommended for ongoing immunological research to better understand unique responses to COVID-19 vaccination. Key messages • End-stage renal disease patients have similar early innate immune responses to COVID-19 vaccination as healthy controls. • Sex-stratification is important to identify unique immunological responses that may be leveraged for sex-specific vaccination strategies.

Infodemics and Vaccine Confidence: Protocol for Social Listening and Insight Generation to Inform Action.

In the fall of 2020, the COVID-19 infodemic began to affect public confidence in and demand for COVID-19 vaccines in the United States. While polls indicated what consumers felt regarding COVID-19 vaccines, they did not provide an understanding of why they felt that way or the social and informational influences that factored into vaccine confidence and uptake. It was essential for us to better understand how information ecosystems were affecting the confidence in and demand for COVID-19 vaccines in the United States. The US Centers for Disease Control and Prevention (CDC) established an Insights Unit within the COVID-19 Response's Vaccine Task Force in January 2021 to assist the agency in acting more swiftly to address the questions, concerns, perceptions, and misinformation that appeared to be affecting uptake of COVID-19 vaccines. We established a novel methodology to rapidly detect and report on trends in vaccine confidence and demand to guide communication efforts and improve programmatic quality in near real time. We identified and assessed data sources for inclusion through an informal landscape analysis using a snowball method. Selected data sources provided an expansive look at the information ecosystem of the United States regarding COVID-19 vaccines. The CDC's Vaccinate with Confidence framework and the World Health Organization's behavioral and social drivers for vaccine decision-making framework were selected as guiding principles for interpreting generated insights and their impact. We used qualitative thematic analysis methods and a consensus-building approach to identify prevailing and emerging themes, assess their potential threat to vaccine confidence, and propose actions to increase confidence and demand. As of August 2022, we have produced and distributed 34 reports to >950 recipients within the CDC and externally. State and local health departments, nonprofit organizations, professional associations, and congressional committees have referenced and used the reports for learning about COVID-19 vaccine confidence and demand, developing communication strategies, and demonstrating how the CDC monitored and responded to misinformation. A survey of the reports' end users found that nearly 75% (40/53) of respondents found them "very" or "extremely" relevant and 52% (32/61) used the reports to inform communication strategies. In addition, our methodology underwent continuous process improvement to increase the rigor of the research process, the validity of the findings, and the usability of the reports. This methodology can serve as a diagnostic technique for rapidly identifying opportunities for public health interventions and prevention. As the methodology itself is adaptable, it could be leveraged and scaled for use in a variety of public health settings. Furthermore, it could be considered beyond acute public health crises to support adherence to guidance and recommendations and could be considered within routine monitoring and surveillance systems.

COVID-19 Vaccination Response in Patients with Multiple Sclerosis Treated with Ofatumumab in the United States: A Medical Record Review.

Real-world data are required to provide a greater understanding of the impact of ofatumumab on the ability to mount an effective immune response following the receipt of approved COVID-19 vaccinations. This retrospective real-world analysis aimed to describe the humoral immune response to COVID-19 vaccination during ofatumumab treatment in patients with multiple sclerosis (MS). Data from patients with MS treated with ofatumumab who were fully vaccinated against COVID-19 infection were abstracted from medical charts at four clinical sites in the USA. Patient characteristics and humoral response were summarized descriptively. Differences in humoral response were documented on the basis of vaccination status during ofatumumab treatment (i.e., after full vaccination and after booster vaccination) and prior disease-modifying treatment (DMT) exposure (i.e., DMT naïve, prior anti-CD20/sphingosine 1-phosphate [S1P] therapy, prior non-anti-CD20/S1P therapy). The sample size precluded formal statistical analysis. Thirty-eight patients were included. The mean (standard deviation) duration of ofatumumab treatment upon data collection was 20.4 (4.6) months (treatment ongoing for 35 [92%] patients). Definitive humoral response after full vaccination was documented for 34 patients, of whom 20 (60%) were seropositive. Definitive humoral response after booster vaccination was documented among five patients, of whom three (60%) were seropositive. Among patients who were DMT naïve prior to ofatumumab (n = 15), 73% were seropositive; among patients exposed to prior anti-CD20/S1P therapy (n = 14), 33% were seropositive; and among patients exposed to prior non-anti-CD20/S1P therapy (n = 9), 56% were seropositive. Patients naïve to DMT had been living with an MS diagnosis for a shorter duration than those experienced with DMTs. Patients with MS receiving ongoing treatment with ofatumumab can mount a positive humoral response to a COVID-19 vaccination. Prior treatment with anti-CD20 or S1P DMTs may be a risk factor for lower humoral response.

Challenges of infectious diseases in older adults: From immunosenescence and inflammaging through antibiotic resistance to management strategies

Infectious diseases in older adults present a significant challenge to the healthcare system, marked by increased morbidity, mortality, and rising costs of care. Age-related changes (ARCs) in the immune system, including immunosenescence and inflammaging, contribute to heightened susceptibility to severe infections and reduced vaccine responsiveness. Additionally, alterations in the normal microbial flora due to aging and factors such as antibiotic therapy predispose older individuals to infections and age-related diseases. Changes in body composition also affect the pharmacokinetics and pharmacodynamics of drugs, complicating the management of antibiotics and leading to potential overdoses, adverse drug reactions, or underdoses that foster antibiotic resistance. The inappropriate use of antibiotics has exacerbated the emergence of multidrug-resistant pathogens, posing a critical global concern. This narrative review provides an overview of immunosenescence and inflammaging and focuses on three major infectious diseases affecting older adults: bacterial pneumonia, urinary tract infections, and Clostridium difficile infections. Through this exploration, we aim to highlight the need for targeted approaches in managing infectious diseases in the aging population.

Identification of three subtypes of ovarian cancer and construction of prognostic models based on immune-related genes

BackgroundImmunotherapy has revolutionized the treatment of ovarian cancer (OC), but different immune microenvironments often constrain the efficacy of immunotherapeutic interventions. Therefore, there is an imperative to delineate novel immune subtypes for development of efficacious immunotherapeutic strategies.MethodsThe immune subtypes of OC were identified by consensus cluster analysis. The differences in clinical features, genetic mutations, mRNA stemness (mRNAsi) and immune microenvironments were analyzed among subtypes. Subsequently, prognostic risk models were constructed based on differentially expressed genes (DEGs) of the immune subtypes using weighted correlation network analysis.ResultsOC patients were classified into three immune subtypes with distinct survival rates and clinical features. Different subtypes exhibited varying tumor mutation burdens, homologous recombination deficiencies, and mRNAsi levels. Significant differences were observed among immune subtypes in terms of immune checkpoint expression and immunogenic cell death. Prognostic risk models were validated as independent prognostic factors demonstrated great predictive performance for survival of OC patients.ConclusionIn this study, three distinct immune subtypes were identified based on gene sets related to vaccine response, with the C2 subtype exhibiting significantly worse prognosis. While no statistically significant differences in tumor mutation burden (TMB) were observed across the three subtypes, the homologous recombination deficiency (HRD) score and mRNA stemness index (mRNAsi) were notably elevated in the C2 group compared to the others. Immune infiltration analysis indicated that the C2 subtype may have an increased presence of regulatory T (Treg) cells, potentially contributing to a more favorable response to combination therapies involving PARP inhibitors and immunotherapy. These findings offer a precision medicine approach for tailoring immunotherapy in ovarian cancer patients. Moreover, the C3 subtype demonstrated significantly lower expression levels of immune checkpoint genes, a pattern validated by independent datasets, and associated with a better prognosis. Further investigation revealed that the immune-related gene FCRL5 correlates with ovarian cancer prognosis, with in vitro experiments showing that it influences the proliferation and migration of the ovarian cancer cell line SKOV3.

Long term T cell response and safety of a tetravalent dengue vaccine in healthy children

As robust cellular responses are important for protection against dengue, this phase 2 study evaluated the kinetics and phenotype of T cell responses induced by TAK-003, a live-attenuated tetravalent dengue vaccine, in 4–16-year-old living in dengue-endemic countries (NCT02948829). Two hundred participants received TAK-003 on Days 1 and 90. Interferon-gamma (IFN-γ) enzyme-linked immunospot assay [ELISPOT] and intracellular cytokine staining were used to analyze T cell response and functionality, using peptide pools representing non-structural (NS) proteins NS3 and NS5 matching DENV-1, -2, -3, and -4 and DENV-2 NS1. One month after the second TAK-003 dose (Day 120), IFN-γ ELISPOT T cell response rates against any peptide pool were 97.1% (95% CI: 93.4% to 99.1%), and similar for baseline dengue seropositive (96.0%) and seronegative (98.6%) participants. IFN-γ ELISPOT T cell response rates at Day 120 were 79.8%, 90.2%, 77.3%, and 74.0%, against DENV-1, -2, -3, and -4, respectively, and remained elevated through 3 years post-vaccination. Multifunctional CD4 and CD8 T cell responses against DENV-2 NS peptides were observed, independent of baseline serostatus: CD8 T cells typically secreted IFN-γ and TNF-α whereas CD4 T cells secreted ≥ 2 of IFN-γ, IL-2 and TNF-α cytokines. NAb titers and seropositivity rates remained substantially elevated through 3 years post-vaccination. Overall, TAK-003 was well tolerated and elicited durable T cell responses against all four DENV serotypes irrespective of baseline serostatus in children and adolescents aged 4–16 years living in dengue-endemic countries. TAK-003-elicited CD4 and CD8 T cells were multifunctional and persisted up to 3 years post-vaccination.

Th1 polarization in Bordetella pertussis vaccine responses is maintained through a positive feedback loop.

Outbreaks of Bordetella pertussis (BP), the causative agent of whooping cough, continue despite broad vaccination coverage and have been increasing since vaccination switched from whole-BP (wP) to acellular BP (aP) vaccines. wP vaccination has been associated with more durable protective immunity and an induced Th1 polarized memory T cell response. Here, a multi-omics approach was applied to profile the immune response of 30 wP and 31 aP-primed individuals and identify correlates of T cell polarization before and after Tdap booster vaccination. We found that transcriptional changes indicating an interferon response on day 1 post-booster along with elevated plasma concentrations of IFN-γ and interferon-induced chemokines that peaked at day 1-3 post-booster correlated best with the Th1 polarization of the vaccine-induced memory T cell response on day 28. Our studies suggest that wP-primed individuals maintain their Th1 polarization through this early memory interferon response. This suggests that stimulating the interferon pathway during vaccination could be an effective strategy to elicit a predominant Th1 response in aP-primed individuals that protects better against infection.

Delayed reinforcement of costimulation improves the efficacy of mRNA vaccines in mice.

mRNA vaccines have demonstrated efficacy during the COVID-19 pandemic and are now being investigated for multiple diseases. However, concerns linger about the durability of immune responses, and the high incidence of breakthrough infections among vaccinated individuals highlights the need for improved mRNA vaccines. In this study, we investigated the effects of reinforcing costimulation via 4-1BB, a member of the TNF receptor superfamily, on immune responses elicited by mRNA vaccines. We first immunized mice with mRNA vaccines, followed by treatment with 4-1BB costimulatory antibodies to reinforce the 4-1BB pathway at different timepoints post-vaccination. Consistent with prior studies, reinforcing 4-1BB costimulation on the day of vaccination did not result in a substantial improvement of vaccine responses. However, reinforcing 4-1BB costimulation at day 4 post-vaccination, when 4-1BB expression levels were highest, resulted in a profound improvement of CD8 T cell responses associated with enhanced protection against pathogen challenges. A similar clinical benefit was observed in a therapeutic cancer vaccine model. We also report time-dependent effects with OX40, another costimulatory molecule of the TNF receptor superfamily. These findings demonstrate that delayed reinforcement of costimulation may exert an immunologic benefit, providing insights for the development of more effective mRNA vaccines for infectious diseases and cancer.

The Ambivalence of Post COVID-19 Vaccination Responses in Humans.

The Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has prompted a massive global vaccination campaign, leading to the rapid development and deployment of several vaccines. Various COVID-19 vaccines are under different phases of clinical trials and include the whole virus or its parts like DNA, mRNA, or protein subunits administered directly or through vectors. Beginning in 2020, a few mRNA (Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273) and adenovirus-based (AstraZeneca ChAdOx1-S and the Janssen Ad26.COV2.S) vaccines were recommended by WHO for emergency use before the completion of the phase 3 and 4 trials. These vaccines were mostly administered in two or three doses at a defined frequency between the two doses. While these vaccines, mainly based on viral nucleic acids or protein conferred protection against the progression of SARS-CoV-2 infection into severe COVID-19, and prevented death due to the disease, their use has also been accompanied by a plethora of side effects. Common side effects include localized reactions such as pain at the injection site, as well as systemic reactions like fever, fatigue, and headache. These symptoms are generally mild to moderate and resolve within a few days. However, rare but more serious side effects have been reported, including allergic reactions such as anaphylaxis and, in some cases, myocarditis or pericarditis, particularly in younger males. Ongoing surveillance and research efforts continue to refine the understanding of these adverse effects, providing critical insights into the risk-benefit profile of COVID-19 vaccines. Nonetheless, the overall safety profile supports the continued use of these vaccines in combating the pandemic, with regulatory agencies and health organizations emphasizing the importance of vaccination in preventing COVID-19's severe outcomes. In this review, we describe different types of COVID-19 vaccines and summarize various adverse effects due to autoimmune and inflammatory response(s) manifesting predominantly as cardiac, hematological, neurological, and psychological dysfunctions. The incidence, clinical presentation, risk factors, diagnosis, and management of different adverse effects and possible mechanisms contributing to these effects are discussed. The review highlights the potential ambivalence of human response post-COVID-19 vaccination and necessitates the need to mitigate the adverse side effects.

Development and characterization of HCMV recombinant subunit vaccines based on T-cell epitopes

Human cytomegalovirus (HCMV), a ubiquitous β-herpes virus, mostly causes asymptomatic infections in adults with healthy immune systems. Due to immunosuppressive therapy, solid organ transplantation (SOT) recipients are at increased risk of HCMV infection. In recent years, the interdisciplinary, filed of immunoinformatics, based on computer science, and modern immunology, has emerged. In this study, we designed three types of recombinant subunit vaccines, which are expressed by the E. coli BL21 strain according to immunoinformatics prediction. Subsequently, we evaluated the innate and cellular immune responses of recombinant subunit vaccines in vivo and/or in vitro. Flow cytometry analysis, revealed that recombinant subunit vaccines enhanced both innate and cellular immune responses in vivo and/or in vitro. We also found that the novel herb adjuvant hesperetin (HES) increased memory T cell inflation. Overall, we developed three types of recombinant subunit vaccines based on HCMV antigen fragments containing multiple T-cell epitopes and assessed the innate and cellular immune responses in vivo and/or in vitro.

Durable Immune Response and Long-term Efficacy of COVID-19 Vaccination in Children With Inflammatory Bowel Disease.

Children with inflammatory bowel disease (IBD) may have diminished serologic response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and increased risk for subsequent severe coronavirus disease 2019 (COVID-19) infection. We sought to describe outcomes among those who developed SARS-CoV-2 infection following vaccination, characterize SARS-CoV-2 antibodies 1 year post-vaccination, and identify factors associated with durable serologic response. We recruited children with IBD who received ≥2 doses of SARS-CoV-2 vaccine and prospectively collected data on (1) demographics, IBD characteristics, and therapy and (2) SARS-CoV-2 vaccination, testing, and infection symptoms. Serum was obtained for measurement of anti-receptor-binding domain IgG antibodies following a 2-part immunization at 12 and 52 weeks. We enrolled 298 participants (mean age 11.9 ± 3.82, 50% female, 67% Crohn's disease). Symptomatic COVID-19 infection after vaccination occurred in half of the participants, although only 2 (1%) required hospitalization. Anti-tumor necrosis factor alpha (TNF-α) was associated with higher likelihood of symptomatic COVID-19 infection, with an adjusted hazard ratio of 2.7 (95% CI, 1.5-5.0; P = .001). Nearly all participants (99%) had detectable antibody at Week 52. Children aged 1-5 years had lower 52-week antibody level compared to older children (P = .04), as did those on anti-TNF-α therapy (P = .007) and those who received only 2 vaccine doses prior to Week 52 (P < .001). SARS-CoV-2 vaccination provides lasting serologic response and protection against severe COVID-19 for most children with IBD, despite the use of lower vaccine doses in younger children and wide-ranging classes of immunosuppressive therapies.

Immunopeptidomics of Salmonella enterica Serovar Typhimurium-Infected Pig Macrophages Genotyped for Class II Molecules.

Salmonellosis is a zoonotic infection that has a major impact on human health; consuming contaminated pork products is the main source of such infection. Vaccination responses to classic vaccines have been unsatisfactory; that is why peptide subunit-based vaccines represent an excellent alternative. Immunopeptidomics was used in this study as a novel approach for identifying antigens coupled to major histocompatibility complex class II molecules. Three homozygous individuals having three different haplotypes (Lr-0.23, Lr-0.12, and Lr-0.21) were thus selected as donors; peripheral blood macrophages were then obtained and stimulated with Salmonella typhimurium (MOI 1:40). Although similarities were observed regarding peptide length distribution, elution patterns varied between individuals; in total, 1990 unique peptides were identified as follows: 372 for Pig 1 (Lr-0.23), 438 for Pig 2 (Lr.0.12) and 1180 for Pig 3 (Lr.0.21). Thirty-one S. typhimurium unique peptides were identified; most of the identified peptides belonged to outer membrane protein A and chaperonin GroEL. Notably, 87% of the identified bacterial peptides were predicted in silico to be elution ligands. These results encourage further in vivo studies to assess the immunogenicity of the identified peptides, as well as their usefulness as possible protective vaccine candidates.

A mathematical model simulating the adaptive immune response in various vaccines and vaccination strategies

Vaccination has been widely recognized as an effective measure for preventing infectious diseases. To facilitate quantitative research into the activation of adaptive immune responses in the human body by vaccines, it is important to develop an appropriate mathematical model, which can provide valuable guidance for vaccine development. In this study, we constructed a novel mathematical model to simulate the dynamics of antibody levels following vaccination, based on principles from immunology. Our model offers a concise and accurate representation of the kinetics of antibody response. We conducted a comparative analysis of antibody dynamics within the body after administering several common vaccines, including traditional inactivated vaccines, mRNA vaccines, and future attenuated vaccines based on defective interfering viral particles (DVG). Our findings suggest that booster shots play a crucial role in enhancing Immunoglobulin G (IgG) antibody levels, and we provide a detailed discussion on the advantages and disadvantages of different vaccine types. From a mathematical standpoint, our model proposes four essential approaches to guide vaccine design: enhancing antigenic T-cell immunogenicity, directing the production of high-affinity antibodies, reducing the rate of IgG decay, and lowering the peak level of vaccine antigen-antibody complexes. Our study contributes to the understanding of vaccine design and its application by explaining various phenomena and providing guidance in comprehending the interactions between antibodies and antigens during the immune process.

Blood transcriptome profiling reveals distinct gene networks induced by mRNA vaccination against COVID-19.

Messenger RNA (mRNA) vaccines represent a new class of vaccines that has been shown to be highly effective during the COVID-19 pandemic and that holds great potential for other preventative and therapeutic applications. While it is known that the transcriptional activity of various genes is altered following mRNA vaccination, identifying and studying gene networks could reveal important scientific insights that might inform future vaccine designs. In this study, we conducted an in-depth weighted gene correlation network analysis of the blood transcriptome before and 24h after the second and third vaccination with licensed mRNA vaccines against COVID-19 in humans, following a prime vaccination with either mRNA or ChAdOx1 vaccines. Utilizing this unsupervised gene network analysis approach, we identified distinct modular networks of co-varying genes characterized by either an expressional up- or downregulation in response to vaccination. Downregulated networks were associated with cell metabolic processes and regulation of transcription factors, while upregulated networks were associated with myeloid differentiation, antigen presentation, and antiviral, interferon-driven pathways. Within this interferon-associated network, we identified highly connected hub genes such as STAT2 and RIGI and associated upstream transcription factors, potentially playing important regulatory roles in the vaccine-induced immune response. The expression profile of this network significantly correlated with S1-specific IgG levels at the follow-up visit in vaccinated individuals. Those findings could be corroborated in a second, independent cohort of mRNA vaccine recipients. Collectively, results from this modular gene network analysis enhance the understanding of mRNA vaccines from a systems immunology perspective. Influencing specific gene networks could lead to optimized vaccines that elicit augmented vaccine responses.

Vaccine responses and hybrid immunity in people living with HIV after SARS-CoV-2 breakthrough infections

The COVID-19 pandemic posed a challenge for people living with HIV (PLWH), particularly immune non-responders (INR) with compromised CD4 T-cell reconstitution following antiretroviral therapy (CD4 count <350 cells per mm3). Their diminished vaccine responses raised concerns about their vulnerability to SARS-CoV-2 breakthrough infections (BTI). Our in-depth study here revealed chronic inflammation in PLWH and a limited anti-Spike IgG response after vaccination in INR. Nevertheless, the imprinting of Spike-specific B cells by vaccination significantly enhanced the humoral responses after BTI. Notably, the magnitude of cellular CD4 response in all PLWH was comparable to that in healthy donors (HD). However, the polyfunctionality and phenotype of Spike-specific CD8 T cells in INR differed from controls. The findings highlight the need for additional boosters with variant vaccines, and for monitoring ART adherence and the durability of both humoral and cellular anti-SARS-CoV-2 immunity in INR.

Clustering Analysis Identified Distinct Clinical Phenotypes among Hemodialysis Patients in Their Immunological Response to the BNT162b2 mRNA Vaccine against SARS-CoV-2.

Background: The 2019 coronavirus disease (COVID-19) pandemic induced a major health crisis worldwide, notably among end-stage kidney disease (ESKD) patients. Vaccination against SARS-CoV-2, especially with messenger RNA (mRNA) vaccines, is highly effective and reduces hospitalization and mortality in both the general and ESKD populations. Age and previous COVID-19 infection have been identified as major determinants of the vaccine response in both the general population and ESKD patients. Methods: To determine the specific phenotype of ESKD patients in relation to their vaccine response, a clustering approach was used in a cohort of 117 fully vaccinated patients. Results: Clustering revealed three distinct clinical phenotypes among hemodialysis patients in terms of immunological response. Two clusters, consisting of either women with a long dialysis history or male subjects with diabetes with a moderate history of dialysis, exhibited low levels of IgG anti-spike antibodies. The third cluster consisted of non-diabetic middle-aged men with a moderate dialysis vintage and a very good serological response to vaccination. Conclusions: These vaccinal phenotypes of dialysis patients are easily identifiable in current practice, allowing for differential serological follow-up and tailored booster SARS-CoV-2 vaccination.

B cell immune repertoire sequencing in tobacco cigarette smoking, vaping, and chronic obstructive pulmonary disease in the COPDGene cohort.

Cigarette smoking (CS) impairs B cell function and antibody production, increasing infection risk. The impact of e-cigarette use ('vaping') and combined CS and vaping ('dual-use') on B cell activity is unclear. To examine B cell receptor sequencing (BCR-seq) profiles associated with CS, vaping, dual-use, COPD-related outcomes, and demographic factors. BCR-seq was performed on blood RNA samples from 234 participants in the COPDGene study. We assessed multivariable associations of B cell function measures (immunoglobulin heavy chain (IGH) subclass expression and usage, class-switching, V-segment usage, and clonal expansion) with CS, vaping, dual-use, COPD severity, age, sex, and race. We adjusted for multiple comparisons using the Benjamini-Hochberg method, identifying significant associations at 5% FDR and suggestive associations at 10% FDR. Among 234 non-Hispanic white (NHW) and African American (AA) participants, CS and dual-use were significantly positively associated with increased secretory IgA production, with dual-use showing the strongest associations. Dual-use was positively associated with class switching and B cell clonal expansion, indicating increased B cell activation, with similar trends in those only smoking or only vaping. We observed significant associations between race and IgG antibody usage. AA participants had higher IgG subclass proportions and lower IgM usage compared to NHW participants. CS and vaping additively enhance B cell activation, most notably in dual-users. Self-reported race was strongly associated with IgG isotype usage. These findings highlight associations between B cell activation and antibody transcription, suggesting potential differences in immune and vaccine responses linked to CS, vaping, and race.

Improved influenza vaccine responses after expression of multiple viral glycoproteins from a single mRNA.

Influenza viruses cause substantial morbidity and mortality every year despite seasonal vaccination. mRNA-based vaccines have the potential to elicit more protective immune responses, but for maximal breadth and durability, it is desirable to deliver both the viral hemagglutinin and neuraminidase glycoproteins. Delivering multiple antigens individually, however, complicates manufacturingand increases cost, thus it would be beneficial to express both proteins from a single mRNA. Here, we develop an mRNA genetic configuration that allows the simultaneous expression of unmodified, full-length NA and HA proteins from a single open reading frame. We apply this approach to glycoproteins from contemporary influenza A and B viruses and, after vaccination, observe high levels of functional antibodies and protection from disease in female mouse and male ferret challenge models. This approach may further efforts to utilize mRNA technology to improve seasonal vaccine efficacy by efficiently delivering multiple viral antigens simultaneously and in their native state.

Role of SARS-CoV-2-specific memory B cells promoting immune protection after booster vaccination in solid organ transplantation.

Solid organ transplant (SOT) recipients display weak seroconversion and neutralizing antibody (NAb) responses after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and remain at risk of severe coronavirus disease 2019 (COVID-19). While B-cell memory is the hallmark of serological immunity, its role in driving successful vaccine responses and providing immune protection in SOT patients remains unclear. We investigated the function and interplay of SARS-CoV-2-specific memory B cells (mBc), different cytokineproducing T cells, and cross-reactive NAb in driving seroconversion and protection against COVID-19 in two cohorts. First, we studied a large cohort of 148 SOT recipients and 32 immunocompetent individuals who underwent several vaccinations. Subsequently, we assessed 25 SOT patients participating in a randomized controlled trial to compare two different immunosuppressive strategies for allowing successful seroconversion and memory-cell responses after booster vaccination. We corroborate previous findings that B- and T-cell memory responses are weaker and more delayed in SOT patients than in immunocompetent (IC) individuals; however, within the SOT cohort, we found that these responses are relatively stronger and more robust in patients not receiving mycophenolate mofetil (MMF)-based therapies. Anti- spike IgG titers strongly correlated with RBD-specific IgG-producing mBc, with both displaying broad viral cross reactivity. Prebooster SARS-CoV-2-specific mBc and IL-2- producing T cells accurately predicted Nab seroconversion (AUC, 0.828) and protection against severe COVID-19. While switching unresponsive SOT patients from calcineurin inhibitors (CNI)/MMF to a low-exposure CNI/mTOR-i regimen favored wider SARS-CoV-2-specific immune responses after a fourth booster vaccination, preformed RBD-specific mBc predicted NAb seroconversion. Our study adds new insights into the pathobiology of immune memory and highlights the pivotal role of SARS-CoV-2-specific mBc in promoting immune protection inSOT patients.