Search Results (219)

Background: Adenoviral vectors are widely used in vaccine development; however, pre-existing immunity to common human adenovirus serotypes can limit their effectiveness. Canine adenovirus type 2 (CAV-2) is a non-human adenovirus with low seroprevalence in humans, making it a suitable alternative vector. Despite its promise, comprehensive preclinical safety data for CAV-2 vector-based vaccine platforms remain limited. In this study, we evaluated the safety profile of a replication-defective CAV-2 vector expressing the Omicron BA.4 SARS-CoV-2 spike immunogen in BALB/c mouse models. Methods: The SARS-CoV-2 CAV-2 vector-based vaccine was expressed and propagated in AD293 cells. The mice received intramuscular prime-boost immunisations with low (1 × 10⁶ PFU), moderate (0.5 × 10¹⁰ PFU), or high (1 × 10¹⁰ PFU) vaccine doses, alongside empty CAV-2 vector and physiological buffer control groups, and were monitored longitudinally up to Day 72. The mice were clinically assessed at days 0, 7, 21, 42, and 72 for any deviations from normal conditions in comparison to the control groups. Biochemical analyses were performed to evaluate liver and kidney function, as well as any tissue injury due to the vaccine candidate. Hematological parameters were assessed by conducting complete blood counts. Body temperature and weight changes were also monitored as an indicator of systemic toxicity. Results: The biochemical and haematological parameters remained within physiological reference ranges across all dose groups and timepoints, with no dose-related deviations, indicating that the vaccine candidate did not show evidence of hepatotoxicity, nephrotoxicity, tissue or haematological toxicity. Body temperatures remained within normal physiological ranges following both prime and booster immunisations, and body weights increased normally across all groups as the animals grew throughout the study period without any abnormal weight gain or loss. Conclusions: These results suggest that the replication-defective CAV-2-vectored SARS-CoV-2 vaccine candidate was well tolerated and did not demonstrate evidence of systemic toxicity under the conditions tested. These findings demonstrate that the CAV-2 vector exhibits a favourable safety profile in murine models when used as a vaccine delivery platform, supporting its translational potential as an alternative adenoviral vector-based vaccine platform. Further studies incorporating additional safety endpoints, including histopathological, vector persistence and shedding evaluation, are warranted to support continued development of the platform. Full article

Human viral entry receptor mouse models exist to overcome a fundamental experimental barrier: many clinically important viruses bind their human entry factors far more efficiently than the corresponding murine orthologs, leaving conventional mice unable to support authentic infection, physiological tissue tropism, or meaningful countermeasure evaluation. This review is organized around the receptor-humanization concept rather than around a single coronavirus model. Engineering strategies compared here include random transgenesis, endogenous-locus knock-in, minimal receptor-interface humanization, conditional and inducible expression, and transient vector-mediated delivery. Receptor systems covered span human angiotensin-converting enzyme 2 (hACE2)-dependent sarbecoviruses, human dipeptidyl peptidase 4 (hDPP4)-dependent Middle East respiratory syndrome coronavirus (MERS-CoV), human cluster of differentiation 4/human C-C chemokine receptor type 5 (hCD4/hCCR5)-dependentt human immunodeficiency virus type 1 (HIV-1), adenovirus receptor models, human intercellular adhesion molecule 1 (hICAM-1) rhinovirus systems, hepatitis C virus (HCV), hepatitis B virus (HBV), and hepatitis D virus (HDV) entry-factor models, measles receptor models, poliovirus receptor/CD155 (PVR/CD155) models, human scavenger receptor class B member 2 (hSCARB2) enterovirus systems, and human transferrin receptor 1 (hTfR1) arenavirus models. We then discuss how these platforms support antibody evaluation, Fc-effector analysis, vaccine protection, variant benchmarking, and safety assessment. These models yield the most reliable data when the experimental question is explicitly entry-dependent and when receptor expression level, anatomical distribution, pathology window, and immune context have all been independently validated. They are least informative when receptor expression is non-physiological, when disease readouts are driven by promoter artifacts, or when post-entry species barriers remain the dominant bottleneck. A validation-centered framework is therefore proposed to guide the selection of each model for the specific antiviral antibody or vaccine question it can legitimately answer. Full article

Adenoviral vectors are widely used for gene therapy and vaccine development. To circumvent pre-existing immunity against commonly used human adenovirus type 5, vectors based on rare human serotype or animal adenoviruses have attracted increasing interest. Previously, we constructed vectors based on fowl adenovirus 4 (FAdV-4) and replaced the knob of FAdV-4 fiber2 with that of FAdV-1 fiber1 to generate FAdV4-CF1K vectors with enhanced transduction efficiency in human cells. In this study, we aimed to modify the packaging system to efficiently produce FAdV-4 vectors carrying transgenes toxic to viral replication. Chicken LMH cells failed to form colonies at low seeding densities. We collected used medium from LMH cell cultures and used it as a supplement to adapt LMH cells, generating the colony-competent subclone LMH-C3532. A lentiviral vector encoding a codon-optimized tetracycline repressor (tetR) was transduced into LMH-C3532 to establish a tetR-integrated cell line, LMH-tetR24. An adenoviral plasmid, pKFAV4-CF1K-CtG, was constructed in which a tetracycline operator (tetO)-bearing CMV promoter controlled GFP expression. The SwaI-flanked GFP in this plasmid was replaced with the HA gene from an H5N1 influenza virus to generate pKFAV4-CF1K-CtHA. Linearized adenoviral plasmids were transfected into LMH-tetR24 cells, and recombinant FAdV4-CF1K-CtG and FAdV4-CF1K-CtHA viruses were successfully rescued, amplified, and purified. When infected with FAdV4-CF1K-CtG at various multiplicities of infection (MOI), the progeny virus yield from LMH-tetR24 cells was 4–10 times higher than that from LMH-C3532 cells. For FAdV4-CF1K-CtHA, the yield difference between the two cell lines was even more pronounced, reaching 3–4 orders of magnitude. Overexpression of HA in LMH-C3532 cells negatively affected FAdV4-CF1K-CtHA replication, resulting in smaller and fewer plaques. In conclusion, by separately integrating tetR into packaging cells and TetO into the adenoviral plasmid, we established a system that can be routinely used to package FAdV-4 vectors. Notably, this system facilitates the propagation of FAdV-4 vectors carrying toxic transgenes. Full article

Background: The dynamics of humoral immune responses following primary and booster COVID-19 vaccinations are crucial to understand in order to optimize vaccination strategies. This study evaluates the magnitude and durability of SARS-CoV-2-specific IgG antibody responses across different vaccines in a large cohort of Bangladeshi adults. Methods: A total of 6300 adults from nine hospitals across eight divisions of Bangladesh were enrolled. Participants received two primary doses of either ChAdOx1 nCoV-19 (Covishield, Serum Institute of India, n = 2855), mRNA-1273 (Moderna, n = 578), BNT162b2 (Pfizer-BioNTech, n = 121), or Vero-cell-inactivated (Sinopharm, n = 2746) vaccines. Booster doses were administered at one-year intervals post-primary vaccination. SARS-CoV-2 spike receptor-binding domain (RBD)-specific IgG antibody responses were measured by ELISA using serum from vaccinees at multiple time points after two primary and two booster doses. Results: A total of 3745 individuals received booster 1 (third dose), with 59% receiving heterologous boosters (a different vaccine regimen than the primary doses). Only 5.5% (n = 347) of participants received a second booster one year after the first booster (among them, 99% received BNT162b2). Our results suggest that heterologous boosters with the mRNA vaccine induced higher IgG levels than homologous boosters for individuals who received primary vaccination with adenovirus vector-based ChAdOx1 nCoV-19 or a Vero-cell-inactivated vaccine. However, in those who initially received the mRNA-based vaccine, both homologous and heterologous boosters produced comparable IgG responses. Among all vaccine types, booster immunization with the Vero-cell-inactivated vaccine induced the lowest antibody responses. Longitudinal analysis demonstrated significantly high IgG levels over the 12 months following the first booster (p < 0.0001); however, IgG levels declined significantly after the second booster dose (fourth dose). Conclusions: Heterologous boosting strategies, particularly those involving mRNA vaccines, elicit stronger and more sustained IgG responses compared to a homologous booster. However, antibody waning after the second booster highlights the need for continued monitoring and potential additional vaccine strategies. Full article

Background: Adenovirus-vectored vaccines played an important role in the global response to SARS-CoV-2. Adenovirus platforms have many advantages including a simple and readily transferred manufacturing process, low cost, and thermostability. Speed of production of an initial Good Manufacturing Practice (GMP)-compliant batch has, however, been viewed as a limitation of adenovirus vectors relative to mRNA platforms. Production of the initial viral starting material and release testing are key rate-limiting steps. Methods: Production of viral starting material from DNA, and release testing in accordance with regulatory expectations, for first-in-human trials of adenovirus-vectored vaccines. Results: We describe experience of these stages in the production of the first GMP batches for multiple adenovirus-vectored candidates and the adaptations made for ChAdOx1 nCoV-19 (the Oxford COVID-19 vaccine) in early 2020. We also report development of a streamlined approach to starting material generation, enabling initial GMP batch availability within c. 60 days of publication of a new pathogen sequence. Using a New World arenavirus vaccine construct as a proof of concept, we demonstrate reproducible execution of this pipeline, maintaining acceptable infectivity and other quality attributes. Conclusions: We discuss opportunities for additional time savings in the future. This work demonstrates suitability of an adenovirus platform to contribute to the “100 Days Mission” for vaccines against “Disease X”. Full article

Human adenovirus (HAdV), a double-stranded DNA virus, targets terminally differentiated cells in the upper respiratory tract. As a key platform for gene therapy vectors, elucidating HAdV’s virulence factors is vital for optimizing therapeutic applications and mitigating risks. To achieve productive replication, HAdV strategically neutralizes host immune defenses and induces S-phase pathways essential for viral propagation. This review synthesizes the latest insights into the key pathways through which HAdVs harness these early proteins to enhance virulence, skilfully evading and counteracting host defense mechanisms while propelling viral replication. As foundational platforms for gene therapy vectors (e.g., in oncology and rare disease treatments) and vaccine backbones (e.g., COVID-19 vaccines like ChAdOx1), understanding HAdV’s immunoshadowing—the multifaceted strategies used to cloak innate and adaptive immunity—is crucial for enhancing vector safety and efficacy. Recent insights unveil how early viral proteins—including E1A, E1B-55K, E4orf1, E4orf3, E4orf6, and the E3 complex—participate in these processes. This review critically synthesizes these pathways, evaluating study limitations such as reliance on immortalized cell lines that underestimate the role of these proteins in immunological competent cells, and addresses unresolved controversies, including differential immunoshadowing efficacy across HAdV species that impacts vaccine design. Full article

Fowl adenovirus serotype 4 (FAdV-4) has been identified as the primary pathogen responsible for hydropericardium-hepatitis syndrome (HHS), resulting in significant economic losses in major poultry-producing countries since 2015. Timely and accurate diagnosis of FAdV-4 infection is essential for the effective prevention and control of HHS. In this study, the two nonstructural genes of FAdV-4, 100K and 22K, were inserted into the expression vector pET-32a (+) respectively. The expressed recombinant proteins were used as coating antigens to develop two indirect ELISA methods, designated as 100K-ELISA and 22K-ELISA. Both ELISAs demonstrated high specificity, showing no cross-reactivity with serum samples positive for other avian diseases. Both ELISAs yielded positive results when applied to 50 serum samples from SPF chickens experimentally infected with FAdV-4 and negative results when applied to 50 serum samples from SPF chickens immunized with an inactivated FAdV-4 vaccine. Similarly, the field sample testing results demonstrated a significant ability to distinguish between vaccinated and infected samples. The 100K-ELISA and 22K-ELISA, which are based on nonstructural proteins, may be effective tools for differentiating between FAdV-4 infection and vaccination, offering a promising approach for differentiating infected from vaccinated animals (DIVA) strategies in poultry. Full article

Background/Objectives: Antigen presenting cells (APCs) and immune cells have unique properties to drive or suppress immune responses. They are therefore key targets for the expression of vaccine antigens or transgene proteins. To better determine the utility of different molecular therapies to modify these cells, mRNA and DNA-based molecular therapy vectors were compared for their ability to genetically modify immune cells after intradermal injections in mice. DNA-based vectors included naked plasmid DNA, plasmid packaged in lipid nanoparticles (LNPs), and replication-defective adenovirus (Ad) vectors. mRNA delivery was mediated by packaging into LNPs like those used in COVID-19 vaccines. Methods: Each vector was used to deliver Cre recombinase into Cre reporter mice whose cells were activated to express green fluorescent protein (GFP) and firefly luciferase after Cre recombination. The mice were injected intradermally (ID) near the base of their tail at a site that drains into the inguinal lymph node. Luciferase activity was imaged in the living mice 1 or 4 days after vector injection. The animals were then euthanized, and luciferase activity was imaged in the draining inguinal lymph node. Cells were prepared from the intradermal injection site and from the draining lymph node to determine which immune cells were genetically modified by phenotyping CD45, CD3, and CD11b GFP-positive cells by flow cytometry. Given that the skin uniquely contains Langerhans dendritic cells, these CD207⁺ cells were also phenotyped in skin samples and in the draining lymph node. Results: In both the skin and in the draining lymph node, the rank order of luciferase and GFP activation by the vectors were: (1) Ad; (2) mRNA-LNP; (3) DNA-LNP; and (4) naked DNA. Only mRNA-LNP and Ad vectors mediated obvious luciferase activity in the living animals and in the draining lymph nodes by imaging. Notably, both vectors appeared to leak from the ID injection site and not only modify the draining lymph node but also strongly modify the livers of the mice. Naked DNA and DNA-LNP mediated detectable GFP activation in the skin and draining lymph node in some mice, but this activity was low and did not reach statistical significance when compared to PBS-treated animals. mRNA-LNPs and Ad both mediated significant Cre delivery in CD45⁺, CD3⁺, CD11b⁺, and CD207⁺ immune cells in the skin and in the lymph node, with adenovirus mediating consistently higher levels of expression in all of the tested cells. Conclusions: These data indicate that mRNA-LNP and Ad vectors mediate stronger modification of skin and lymph node immune cells after intradermal injections. Naked DNA and DNA-LNPs were markedly less potent at this activity than the other vectors. These data are consistent with the higher vaccine potency of mRNA-LNP and Ad vectors and suggest that approaches that increase targeting of immune cell subsets may have utility to increase efficacy while also reducing off-target modification of tissues like the liver. Full article

Background/Objectives: The rapid development of safe and efficacious vaccines is often hindered by extensive, mandated non-clinical safety evaluations in animals. With the aim to provide scientific evidence supporting a “vaccine platform approach”, here we present the complete non-clinical studies for two investigational vaccines, GRAd-COV2 and GRAdHIVNE1, based on GRAd, a gorilla-derived group C adenoviral vector. Methods: The biodistribution of GRAd genomes following the intramuscular administration of the vaccines was assessed in rats by a sensitive qPCR method. Local tolerance and systemic toxic effects were evaluated in single- and repeated-dose toxicity studies in rabbits. Results: GRAd-COV2 and GRAdHIVNE1 were well-tolerated. Distribution was highly confined to the injection site and draining lymph nodes, and toxicity profile consisted of transient, non-adverse inflammatory responses, while the expected immune responses to the encoded antigens were successfully induced. Notably, both vaccines demonstrated a consistent safety profile despite transgene and backbone differences, comparable to other replication-defective adenoviral vectors. Conclusions: The established non-clinical safety profile of the GRAd platform provides a robust foundation for a more efficient and streamlined regulatory pathway. By leveraging this prior knowledge, future GRAd-based vaccines can achieve accelerated clinical development while fully adhering to the ethical principles of replacement, reduction, and refinement of animal use in research. Full article

Bovine viral diarrhea virus (BVDV) is a major pathogen inflicting substantial economic losses on the global cattle industry. To develop a more effective vaccine, we constructed two novel bicistronic recombinant adenoviruses, rAdV-I E0+I E2 and rAdV-I E2+II E2, and systematically evaluated their immunogenicity and protective efficacy in BALB/c mice. Both vaccine candidates, particularly rAdV-I E2+II E2, provoked a robust and rapid neutralizing antibody response that was significantly superior to a commercial inactivated vaccine. They also elicited a potent Th1-skewed cellular immune response, as indicated by significantly higher IFN-γ secretion, and a balanced profile of BVDV-specific IgG and its subclasses. Upon BVDV challenge, immunization with both recombinant vaccines, especially rAdV-I E2+II E2, resulted in a comprehensive reduction in viral loads across all tested tissues (blood, spleen, lungs, kidneys, and small intestine), demonstrating broader protection than the inactivated vaccine. Concordantly, histopathological analysis confirmed that vaccination preserved the normal architecture of the duodenum and spleen, preventing the significant pathological damage observed in the rAdV-empty negative control group. Our findings demonstrate that these adenovirus-vectored vaccines, particularly rAdV-I E2+II E2, induce a multifaceted and protective immune response, highlighting their promise as superior candidates against BVDV. Full article

Background/objectives: RSV is a major cause of mortality in infants, and despite recent progress to prevent RSV in the very young, an RSV vaccine for this population is still highly warranted. Clinical studies in infants in the 1960s using formalin-inactivated RSV (FI-RSV) led to life-threatening enhanced respiratory disease (ERD). Therefore, a thorough safety assessment of RSV vaccine candidates intended for RSV seronegative infants is crucial. Methods: Prior to clinical pediatric development of Ad26.RSV.preF, an adenovirus type 26 vector-encoding RSV F protein stabilized in its prefusion conformation, predisposition to ERD was extensively assessed in cotton rat and mouse models. Results: Cotton rats intramuscularly immunized with a wide dose range of Ad26.RSV.preF, including low and sub-protective vaccine doses, and challenged with vaccine homologous RSV A2 or heterologous RSV B Wash 18537, did not show signs of predisposition to ERD. Histopathology scores for alveolitis, peribronchiolitis, interstitial pneumonia, and perivasculitis after challenge were significantly lower for Ad26.RSV.preF-immunized cotton rats compared to FI-RSV-immunized cotton rats and comparable to or lower than scores in cotton rats intranasally pre-exposed to RSV prior to challenge to mimic natural repeated infection. These results were observed in animals with or without viral replication in the lung after RSV challenge, in the presence or absence of vaccine-induced antibodies. Similar results were observed in mice, where more extensive assessment of mono- and polymorphonuclear cell alveolitis, mucus cell hyperplasia, and mucus accumulation was performed. Conclusions: Based on these extensive analyses, we conclude that there are no indications of ERD predisposition after Ad26.RSV.preF vaccination in rodent models, irrespective of the vaccine dose, challenge virus strain, or presence of viral replication in the lung. These results are crucial for the pediatric development of this vaccine. Full article

Background: Developing an effective vaccine is crucial for the prevention and control of AIDS. Viral vector-based vaccines, particularly those utilizing homologous or heterologous prime-boost strategies, represent an important direction in current HIV vaccine research. Methods: In this study, replication-defective chimeric adenovirus Ad5F35 and modified vaccinia virus Ankara (rMVA) vector vaccines expressing the HIV-1 AEgp145 were successfully constructed, designated as Ad5F35-AEgp145 and rMVA-AEgp145, respectively. Sixty BALB/c mice were randomly divided into three groups: Ad5F35 alone, rMVA prime/Ad5F35 boost, and PBS control. The mice were immunized intramuscularly at weeks 0 and 3, and humoral and cellular immune responses were assessed at 4, 8, 12, and 16 weeks after the initial immunization. Results: The homologous Ad5F35 and heterologous rMVA/Ad5F35 vaccination regimens elicited comparable levels of HIV Env-specific cellular immune responses, peaking at 2100 ± 222 SFCs/million splenocytes and 2200 ± 619 SFCs/million splenocytes, respectively (p > 0.05). Compared to the heterologous regimen, the homologous Ad5F35 regimen induced significantly higher levels of gp120-binding antibodies at weeks 4 and 8 post-initial immunization, with geometric mean titers of 1:25,600 ± 7011 versus 1:1280 ± 150.7 and 1:10,240 ± 4048 versus 1:2560 ± 391.9, respectively. Furthermore, neutralizing activity at week 8 was significantly higher in the homologous group, with a 50% neutralization titers of 1:45 compared to 1:12 in the heterologous group (p < 0.01). Conclusion: This study demonstrates that the Ad5F35-AEgp145 vaccine, whether administered alone or in combination with rMVA-AEgp145, effectively induces strong and comparable cellular immune responses targeting HIV-1 Env in mice. While both regimens are effective, homologous immunization elicits moderately higher levels of antibody responses. These findings provide an important foundation for the further investigation of vector-based HIV vaccine formulations. Full article

Background: The development of effective tuberculosis (TB) vaccines beyond BCG remains an urgent global health priority, especially for prevention of pulmonary TB in adults. While most current strategies focus on enhancing T-cell immunity, the potential of trained immunity to broadly augment both innate and adaptive responses remains underexplored in TB vaccinology. Given the central role of dendritic cells (DCs) as bridges between innate and adaptive immunity, we hypothesized that inducing trained immunity in DCs could optimize subsequent T-cell responses. Previous studies have identified Rv2299c as a promising adjuvant of other antigens by promoting DC maturation; however, whether it could be used as a standalone protective antigen of TB vaccine remains unclear. Methods: We constructed a chimpanzee adenovirus-vectored TB vaccine candidate expressing Rv2299c (rAd-Rv2299c), and evaluated its immunogenicity and protective efficacy in murine models. Results: rAd-Rv2299c vaccine effectively induced a trained immunity phenotype in DCs, as evidenced by upregulated MHC-II and CD86 expression and increased pro-inflammatory cytokine (TNF-α, IL-6, IL-1β and IL-12p70) secretion. Moreover, its immunization promoted the generation of antigen-specific polyfunctional T cells, and robustly enhanced both Th1 and Th17-type immune responses. In a murine challenge model, vaccination significantly reduced bacterial loads in the lung and spleen and attenuated pulmonary inflammation, which was associated with robust recall T-cell immune responses. Conclusions: rAd-Rv2299c confers anti-TB protection by inducing trained immunity in DCs and promoting polyfunctional T-cell responses, thereby offering valuable experimental evidence and conceptual insights for the development of next-generation TB vaccines. Full article

Background/Objectives: In previous studies, we demonstrated that the HIV-1 Env-Gag VLP mRNA vaccine elicited superior cellular immune responses. In this study, we further evaluated the immunogenicity of the Env-Gag VLP mRNA and adenovirus vector vaccines when administered individually or in combination in mice. Methods: BALB/c mice were divided into four groups and immunized twice at a 3-week interval. The three groups received either the Env-Gag VLP mRNA vaccine, the adenovirus vector vaccines expressing env and gag genes, or PBS as a control. The fourth group received a prime-boost regimen, primed with the Env-Gag mRNA vaccine and boosted with the adenovirus vector vaccines. The HIV-1 specific cellular and humoral immune responses were measured 1, 2, 4 and 8 weeks after the last immunization. Results/Conclusions: The results showed that the mRNA vaccines prime-adenovirus vector vaccines boost elicited higher cellular immune responses than those induced by homologous regimens at multiple time points, especially 8 weeks after the last immunization. Although the level of gp120 binding antibody in the combined immunization group is significantly lower than that of in the VLP mRNA vaccine group, a more balanced Th1/Th2 responses were induced in the combined immunization group, and significantly higher and longer-lasting neutralizing antibody levels were detected in this group making it a very promising HIV vaccine strategy. Full article

Background/Objectives: Varicella-zoster virus (VZV) causes herpes zoster (HZ/shingles), particularly in older adults with weakened cell-mediated immunity (CMI), which is essential for controlling VZV reactivation and reducing HZ severity. Currently vaccines, like recombinant subunit or live-attenuated vaccine, showed shortcomings in eliciting CD8⁺ T-cell responses. Addressing this, we utilized the novel replication-defective chimpanzee adenovirus vector ChAdOx1 to construct the ChAdOx1-VZV (CVE) vaccine, using full-length glycoprotein E (gE) as antigen. This study evaluated the immunogenicity of a heterologous intramuscular (IM) prime/intranasal (IN) boost regimen with the aim of developing a novel VZV vaccine candidate. Methods: BALB/c mice were immunized with CVE using homologous or heterologous prime-boost regimens via IM or IN. And cynomolgus macaques were immunized intramuscularly with three doses of CVE. Cellular responses were assessed by intracellular cytokine staining (ICS) and IFN-γ ELISpot using splenocytes and PBMCs. Humoral responses were evaluated by serum gE-IgG ELISA and bone-marrow LLPC ELISpot. Memory subsets and tissue-resident T cells were analyzed by flow cytometry. Results: Heterologous IM prime/IN boost CVE regimen markedly enhanced both cellular and humoral responses, especially CD8⁺ T-cell responses. The induced LLPC and memory T cell responses indicate the potential for long-term protection against herpes zoster. In cynomolgus macaques, CVE induced robust serum gE-specific IgG responses and strong IFN-γ secreting T-cell activity, supporting the immunogenicity of CVE in a genetically distinct primate model and enhancing its clinical translational potential. Conclusions: CVE induces potent cellular and humoral immunogenicity, with IM prime/IN boost vaccination. Cross species immunogenicity observed in nonhuman primates further strengthens the translational relevance of this platform. These findings support CVE as a promising herpes zoster vaccine candidate and provide a rationale for continued evaluation in human-relevant systems. Full article