Open AccessArticle Identification of Conserved Cross-Reactive B-Cell Epitopes in CPV1 and CPV2 L1 Proteins with Vaccine Potential 1 Laboratory of Animal Disease Prevention and Control and Animal Model, Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha 410128, China 2 Department of Chemistry, University College London, London WC1H 0AJ, UK 3 College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China * Authors to whom correspondence should be addressed. † These authors contributed equally to this work. Vaccines 2026, 14(6), 512; https://doi.org/10.3390/vaccines14060512 (registering DOI) Submission received: 5 April 2026 / Revised: 3 June 2026 / Accepted: 3 June 2026 / Published: 6 June 2026 Background/Objectives: Canine papillomavirus (CPV) is an important viral pathogen associated with papillomatosis in dogs, with canine papillomavirus type 1 (CPV1) and type 2 (CPV2) among the most prevalent and clinically relevant genotypes. The L1 capsid protein is a major immunogenic antigen of papillomaviruses; however, conserved linear B-cell epitopes shared between CPV genotypes remain poorly defined. This study aimed to identify conserved cross-reactive B-cell epitopes within CPV1 and CPV2 L1 proteins and to evaluate their preliminary immunoreactivity. Methods: Conserved linear B-cell epitopes were predicted through integrated bioinformatic and structural analyses based on sequence conservation and surface accessibility. Three candidate epitopes were selected. Recombinant CPV1 and CPV2 L1 proteins were expressed in Escherichia coli ( E. coli), purified, used as recombinant L1 antigens, together with BSA-conjugated synthetic epitope peptides for mouse immunization. Antigen-specific IgG responses were assessed by ELISA, antigen-associated IFN-γ responses were evaluated by ELISpot, and cross-reactive antibody recognition was assessed by Western blot. Results: Recombinant L1 proteins induced strong antigen-specific IgG responses in mice. The selected peptides induced detectable but weaker humoral responses compared with the recombinant L1 proteins. Among the three epitopes, TPSGSLV and TVVDNTR elicited antibodies that recognized both CPV1 and CPV2 L1 proteins, while the epitope VIVPKVS showed minimal or no detectable immunoreactivity. ELISpot analysis showed only modest antigen-associated IFN-γ responses, particularly in peptide-immunized groups. Conclusions: This study identified conserved cross-reactive linear B-cell epitope candidates within CPV1 and CPV2 L1 proteins and provided preliminary immunological evidence supporting their potential relevance for CPV antigen design. However, peptide-induced responses were weaker than those induced by recombinant L1 proteins, and VLP formation, antibody neutralizing activity, and protective efficacy were not evaluated. Further studies in dogs, including optimized antigen-display platforms, neutralization assays, and protection studies, are required to determine the practical value of these epitopes for CPV vaccine development. canine papillomavirus; L1 protein; antigenic epitope; immunogenicity; vaccine development 1. Introduction Canine papillomavirus (CPV), a member of the Papillomaviridae family, is a small, non-enveloped virus with a circular double-stranded DNA genome that primarily infects stratified squamous epithelial cells of canine skin and mucosa [ 1, 2, 3]. CPV infection usually causes benign papillomas; however, persistent infection or infection in immunocompromised hosts may contribute to lesion progression and, in rare cases, malignant transformation [ 2, 3, 4]. With the continued expansion of the global companion dog population and increasing attention to preventive veterinary medicine, CPV-associated diseases are receiving greater clinical relevance. However, no licensed prophylactic vaccines are currently available for CPV infection, underscoring the need for improved antigen discovery and vaccine-development strategies [ 2]. However, the antigenic landscape of CPV L1 proteins remains incompletely characterized, particularly with respect to conserved antigenic regions shared between CPV genotypes. Although conformational epitopes presented by native L1 VLPs are central to protective papillomavirus immunity, conserved linear B-cell epitopes may also have value for cross-reactive antigen design, immunodiagnostic development, and incorporation into optimized multi-epitope or complementary vaccine platforms. Linear epitopes are especially suitable for sequence conservation analysis across related viral genotypes and can be readily adapted for synthetic peptide-based screening and antigen engineering. In the present study, we aimed to identify conserved linear B-cell epitopes within the L1 proteins of CPV1 and CPV2 through comprehensive bioinformatic and structural analyses. Candidate epitopes were assessed based on predicted antigenicity, sequence conservation, structural accessibility, and non-toxicity. Recombinant L1 proteins expressed in a prokaryotic system were used as recombinant L1 antigens, together with BSA-conjugated synthetic epitope peptides, to evaluate humoral immunoreactivity and cross-reactive antibody recognition in a mouse model. This study identifies conserved cross-reactive B-cell epitope candidates in CPV1 and CPV2 L1 proteins and provides preliminary immunological information that may support future CPV antigen design and vaccine-related studies. 2. Materials and Methods 2.1. Bioinformatic Prediction and Structural Analysis The secondary and tertiary structures of CPV1 and CPV2 L1 proteins were analyzed to facilitate antigenic epitope identification. Secondary structural elements, including α-helices, β-strands, and random coils, were predicted using PSIPRED (version 4.0). Linear B-cell epitopes were predicted using ABCpred and Bcepred v2.0. To improve prediction specificity, ABCpred analysis was performed using a threshold of 0.7, which is more stringent than the default threshold of 0.51. Candidate epitopes were further evaluated for evolutionary conservation using the ConSurf server and screened for potential toxicity using ToxinPred 2.0. Three-dimensional structures of CPV1 and CPV2 L1 proteins were generated using AlphaFold, and predicted epitopes were mapped onto the modeled structures using PyMOL version 2.5 to assess their spatial localization and predicted surface accessibility. Based on integrated analysis of predicted antigenicity, sequence conservation, non-toxicity, and structural accessibility, the selected peptides were used to identify minimal conserved linear B-cell motifs shared between CPV1 and CPV2 L1 proteins, rather than optimized T-cell epitopes or confirmed protective vaccine antigens. 2.2. Epitope Peptide Synthesis and BSA Conjugation Three conserved epitope peptides (VIVPKVS, TPSGSLV, and TVVDNTR) were synthesized by standard solid-phase peptide synthesis by GenScript Biotech, Nanjing, China, with >95% purity. A terminal cysteine residue was added to each peptide during synthesis to enable maleimide-mediated conjugation to bovine serum albumin (BSA), according to the manufacturer’s protocol. The BSA-conjugated peptides were purified by high-performance liquid chromatography (HPLC) and verified by mass spectrometry (MS) before use. 2.3. Generation of Recombinant Plasmids Full-length coding sequences of CPV1 L1 and CPV2 L1 were obtained based on reference sequences of CPV1 (GenBank accession no. D55633) and CPV2 (GenBank accession no. AY722648). The coding sequences were codon-optimized for prokaryotic expression, synthesized, and fused with an N-terminal 6×His tag by Tsingke Biotechnology Co., Ltd., Beijing, China. The optimized CPV1 L1 gene was cloned into the pCold I expression vector, whereas the CPV2 L1 gene was inserted into the pET-28a(+) vector, generating recombinant plasmids pCold I-CPV1 L1 and pET-28a-CPV2 L1, respectively. Escherichia coli BL21 (DE3) competent cells were purchased from Beijing Bomaide Gene Technology Co., Ltd., (Beijing, China), and used for recombinant protein expression. 2.4. Expression and Purification of Recombinant CPV1 and CPV2 L1 Proteins Recombinant plasmids pCold I-CPV1 L1 and pET28a-CPV2 L1 were transformed into E. coli BL21 (DE3) competent cells. Transformed bacteria were cultured in LB medium at 37 °C until the optical density at 600 nm (OD600) reached 0.6–0.8. CPV1 L1 expression was induced using the pCold system at 16 °C for 24 h, whereas CPV2 L1 expression was induced with 0.5–1 mM IPTG at 25 °C for 10 h. Cells were harvested by centrifugation and lysed by ultrasonic sonication on ice. After clarification by centrifugation, His-tagged L1 proteins were purified using Ni-NTA affinity chromatography, buffer-exchanged into PBS and stored at −80 °C until further use. Purified CPV1 and CPV2 L1 proteins were used as recombinant L1 protein antigens directly in this study in the absence of VLP formation analysis by structural methods such as non-reducing SDS-PAGE, native PAGE, size-exclusion chromatography, dynamic light scattering, or transmission electron microscopy. 2.5. SDS-PAGE and Western Blot Analysis of Recombinant Protein Expression Protein samples were separated by SDS-PAGE on 10% polyacrylamide gels under reducing conditions, alongside a prestained protein molecular weight marker. Proteins were transferred onto PVDF membranes using a semi-dry transfer system at 20 V for 40 min. Membranes were blocked with 5% skim milk in PBST for 1 h at room temperature and incubated overnight at 4 °C with mouse anti-His monoclonal antibody at a 1:5000 dilution. After washing with PBST, membranes were incubated with HRP-conjugated goat anti-mouse IgG secondary antibody at a 1:5000 dilution for 1 h at room temperature. Immunoreactive signals were detected using enhanced chemiluminescence substrate (Thermo Fisher Scientific, Waltham, MA, USA). Protein identity was supported by the expected molecular weight, inducible expression pattern, and anti-His immunoblot reactivity of the purified recombinant proteins. 2.6. Animal Immunization and Welfare Monitoring Female BALB/c mice (6-week-old, n = 30) were purchased from Hunan Slack Jingda Laboratory Animal Co., Ltd., (Changsha, Hunan), and acclimated for one week under specific pathogen-free (SPF) conditions. All animal procedures were conducted in accordance with institutional guidelines for the care and use of laboratory animals. Mice were randomly assigned to six groups, with five mice per group: Group 1, recombinant CPV1 L1 protein; Group 2, recombinant CPV2 L1 protein; Group 3, BSA-conjugated peptide 1; Group 4, BSA-conjugated peptide 2; Group 5, BSA-conjugated peptide 3; and Group 6, naïve control. Purified recombinant CPV1/CPV2 L1 proteins or BSA-conjugated synthetic peptides were emulsified with Freund’s complete adjuvant for primary immunization and Freund’s incomplete adjuvant for booster immunizations. Proteins, 10 μg per mouse, or BSA-conjugated peptides, 50 μg per mouse, were administered subcutaneously in a total volume of 100 μL on day 0, followed by booster immunizations on days 14 and 28. Blood samples were collected on days 14, 28, and 42, and spleens were harvested on day 42 for immunological assays. Animals were monitored daily after immunization for general health, injection-site reactions, mobility, behavior, and body weight. Humane endpoint criteria included severe local inflammation, impaired mobility, abnormal behavior, marked distress, or body weight loss exceeding 20%. 2.7. Sample Collection 2.7.1. Serum Preparation Blood samples were collected from the retro-orbital plexus under anesthesia. After clotting at room temperature, samples were centrifuged at 800× g for 10 min at 4 °C, sera were collected and stored at −20 °C or −80 °C until further analysis. 2.7.2. Splenocyte Isolation Spleens were aseptically harvested after euthanasia. Single-cell suspensions were prepared by mechanical dissociation through a 200-mesh nylon cell strainer in RPMI-1640 medium. Mononuclear cells were isolated by density gradient centrifugation, washed, counted, and resuspended in RPMI-1640 medium containing 10% fetal bovine serum for subsequent assays. 2.8. Immunological Assays 2.8.1. Indirect ELISA Indirect ELISA was performed to evaluate antigen-specific IgG responses in mouse sera. ELISA plates were coated overnight at 4 °C with purified recombinant CPV1 L1 or CPV2 L1 protein at 5 μg/mL in carbonate buffer, pH 9.6, depending on the immunization group and assay purpose. Sera from mice immunized with recombinant CPV1 L1 or CPV2 L1 were tested against the corresponding homologous recombinant L1 protein. For peptide-immunized groups, plates were coated with recombinant CPV1 and/or CPV2 L1 proteins to determine whether peptide-induced antibodies recognized the recombinant L1 antigens and showed cross-reactive binding. Plates were blocked with 5% skim milk in PBST and incubated with serially diluted mouse sera at 37 °C for 1 h. After washing, HRP-conjugated goat anti-mouse IgG at a 1:5000 dilution was added and incubated for 1 h at 37 °C. Color development was performed using TMB substrate and terminated with 2 M H 2SO 4. Optical density was measured at 450 nm using a microplate reader. Samples were considered ELISA-positive when the OD 450 value was at least twofold higher than the mean OD450 value of the negative control sera. 2.8.2. IFN-γ ELISpot Assay IFN-γ ELISpot assays were performed using a precoated IFN-γ ELISpot kit (Dakewe Biotech, Shenzhen, Guangdong, China) according to the manufacturer’s instructions. Splenocytes were seeded at 4 × 10 6 cells/well in IFN-γ ELISpot plates and stimulated with recombinant CPV1/CPV2 L1 proteins or synthetic peptides at 10 μg/mL. Parallel wells without antigen stimulation were included as background controls. PMA stimulation was used as a positive control. After incubation, IFN-γ spot-forming cells were developed and counted according to the manufacturer’s instructions. Antigen-specific responses were calculated by subtracting the number of spots in unstimulated wells from those in antigen-stimulated wells. A response was considered positive when spot numbers were above background and at least twofold higher than the corresponding unstimulated control. Given the low number of IFN-γ-secreting cells observed in peptide-stimulated wells, ELISpot data were interpreted cautiously as supportive evidence of antigen-associated cellular responses rather than definitive T-cell epitope activity. 2.8.3. Western Blot Analysis of Antigenicity Reactivity Purified L1 proteins were separated by SDS-PAGE and transferred onto PVDF membranes. Membranes were blocked with 5% skim milk in PBST for 1 h at room temperature and incubated with mouse anti-L1 or anti-peptide immune sera at a 1:500 dilution, followed by HRP-conjugated goat anti-mouse IgG at a 1:5000 dilution. Immunoreactive signals were detected using an enhanced chemiluminescence substrate. Weak bands comparable to those observed in negative-control serum lanes were interpreted as background or non-specific signals and were not considered definitive antigen-specific reactivity. Full Western blot images can be found in File S1. 2.9. Statistical Analysis All experiments were performed with at least three independent biological replicates. Quantitative data are presented as the mean ± standard deviation (SD). Statistical analyses were conducted using GraphPad Prism software (version 9.0, GraphPad Software, Boston, MA, USA). Normality was assessed using the Shapiro–Wilk test, and homogeneity of variance was evaluated using Levene’s test before parametric analysis. For multiple-group comparisons, one-way ANOVA followed by Tukey’s post hoc test was used when assumptions of normality and equal variance were met; otherwise, the Kruskal–Wallis test followed by Dunn’s multiple-comparisons test was applied. For datasets with relatively small sample sizes, including Figure 5, the Kruskal–Wallis test followed by Dunn’s multiple-comparisons test was used. Comparisons between two groups were performed using Student’s t-test when appropriate. A p value 0.05). Humoral immune responses induced by CPV1 and CPV2 L1 proteins and peptide immunization. Indirect ELISA was performed to evaluate antigen-specific IgG responses in sera from immunized mice. Plates were coated with purified recombinant CPV1 L1 or CPV2 L1 protein, as indicated. ( A) Time course of antigen-specific IgG titers in serum collected at 14, 28, and 42 days after primary immunization. ( B) Antigen-specific IgG levels measured in serially diluted sera (10 −2–10 −7). Data are presented as mean ± SD ( n = 5 mice per group). Statistical significance among groups was analyzed using the Kruskal–Wallis test followed by Dunn’s multiple-comparisons test. A p value 0.05). 3.7. Cellular Immune Responses Splenocytes isolated on day 42 primary immunization were stimulated in vitro with recombinant CPV1 and CPV2 L1 proteins or epitope peptides, and IFN-γ secretion were assessed by ELISpot. Parallel unstimulated wells were included as background controls, and antigen-specific responses were calculated after background subtraction. The positive control induced robust IFN-γ spot formation, confirming the functional responsiveness of the isolated splenocytes ( Figure 6). Recombinant L1 protein-stimulated groups showed detectable IFN-γ responses, whereas peptide-stimulated groups showed low IFN-γ spot numbers that were not statistically significant compared with the negative control group. Therefore, although peptide-immunized groups showed detectable IFN-γ spot formation, the current data do not provide sufficient evidence that the tested short peptides directly induced robust T-cell activation. These results are best interpreted as limited or modest antigen-associated cellular responses under the experimental conditions used. 3.8. Antigenic Reactivity and Cross-Reactive Recognition of CPV1/CPV2 L1 Proteins Western blot analysis was performed to determine whether antibodies induced by recombinant L1 proteins or selected peptides could recognize CPV1 and CPV2 L1 antigens. Purified recombinant CPV1 and CPV2 L1 proteins were used as target antigens, and immune sera from vaccinated mice were used as primary antibodies. Sera from mice immunized with recombinant CPV1 or CPV2 L1 proteins showed strong reactivity with recombinant L1 antigens, with bands detected at approximately 55–60 kDa ( Figure 7), indicating that recombinant L1 protein immunization induced antibodies capable of recognizing L1 antigens. Among peptide-immunized groups, sera against peptide 2 (TPSGSLV) and peptide 3 (TVVDNTR) showed detectable recognition of both CPV1 and CPV2 L1 proteins, suggesting cross-reactive antibody binding, whereas peptide 1 (VIVPKVS) serum showed minimal or no clear immunoreactivity. A faint signal observed in one CPV2 lane probed with peptide 1 serum was comparable to the weak signal in the negative-control lane and was therefore interpreted as likely background or non-specific reactivity rather than definitive peptide-specific recognition. Only bands clearly stronger than the negative-control background were considered specific antigen-reactive signals. These results suggest that TPSGSLV and TVVDNTR are conserved linear B-cell epitope candidates with cross-reactive antigen-binding potential, although neutralizing activity and protective efficacy remain to be determined. 4. Discussion Papillomavirus L1 is the major capsid protein and a central target of humoral immune responses. In HPV, licensed L1-based VLP vaccines provide strong protection primarily by inducing neutralizing antibodies against conformational epitopes displayed on the native three-dimensional VLP surface [ 9, 11, 14, 30, 31, 32, 33, 34]. Therefore, conformational epitopes and assembled VLP structures remain the most established basis for protective papillomavirus vaccination. The continued clinical importance of HPV-associated diseases also supports ongoing refinement of papillomavirus vaccine strategies [ 35, 36, 37, 38]. The present study does not challenge this principle, rather, it focuses on conserved linear B-cell epitopes within CPV1 and CPV2 L1 proteins as candidate antigenic motifs that may be useful for cross-reactive antigen design, immunodiagnostic development, or incorporation into future optimized multi-epitope or display-based platforms [ 39, 40, 41, 42, 43, 44, 45]. Using integrated bioinformatic and structural analyses, we identified three conserved or highly similar linear motifs, VIVPKVS, TPSGSLV, and TVVDNTR, within CPV1 and CPV2 L1 proteins. These epitopes were selected based on predicted antigenicity, sequence conservation, non-toxicity, and predicted structural accessibility. Structural mapping suggested that the selected motifs were located in surface-accessible or transitional regions of the predicted L1 structures, supporting their potential availability for antibody recognition. However, because these structural data were derived from computational models, they should be interpreted as supportive evidence rather than direct experimental proof of native epitope exposure. Among the three tested peptides, TPSGSLV and TVVDNTR induced sera that recognized both recombinant CPV1 and CPV2 L1 proteins by Western blot, suggesting cross-reactive antigen binding. In contrast, VIVPKVS showed minimal or no clear immunoreactivity. These findings indicate that TPSGSLV and TVVDNTR may represent truly conserved cross-reactive linear B-cell epitope candidates. However, antibody binding detected by ELISA or Western blot does not necessarily indicate neutralizing activity. Because live-virus or pseudovirus neutralization assays were not performed, the functional relevance of the peptide-induced antibodies remains undetermined. Several limitations should be emphasized. First, immunogenicity was evaluated in mice rather than in dogs, the natural host of CPV infection. Second, peptide-induced antibody responses were weaker and less consistent than those induced by recombinant L1 proteins. Third, neutralizing activity and protective efficacy were not assessed. Fourth, VLP assembly or native oligomeric status of recombinant L1 proteins was not experimentally determined. Finally, the short peptides used in this study were designed to identify minimal conserved linear B-cell motifs, not optimized vaccine-ready antigens or T-cell epitopes. In conclusion, this study identified conserved cross-reactive linear B-cell epitope candidates within the L1 proteins of CPV1 and CPV2. Among the three selected peptides, TPSGSLV and TVVDNTR showed detectable cross-reactive antibody recognition of recombinant CPV1 and CPV2 L1 proteins, whereas VIVPKVS showed minimal or no clear immunoreactivity. Recombinant L1 proteins induced stronger humoral responses than the short synthetic peptides, indicating that these minimal linear epitopes are unlikely to function effectively as standalone immunogens. The present findings provide preliminary immunological evidence and candidate epitope information that may support future CPV antigen design. However, the peptide-induced responses were weaker than those elicited by recombinant L1 proteins, and the neutralizing activity, protective efficacy, native oligomeric status, and VLP formation of the recombinant L1 proteins were not evaluated in this study. Further studies in dogs, including optimized antigen-display systems, structural characterization, neutralization assays, and protection experiments, will be required to determine the practical value of these epitopes for CPV vaccine development. 6. Patent The authors declare that a patent application has been filed covering aspects of the conserved epitopes and their potential applications in vaccine development described in this study. Supplementary Materials The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/vaccines14060512/s1, File S1: Full Western blot images. Author Contributions Conceptualization, Y.Y. (Yi Yang), N.W., D.D. and A.W.; Methodology, Y.W.; Software, Y.W. and Y.C.; Validation, Y.W., Y.C. and K.W.; Formal analysis, Y.W., Y.C., K.W., Y.Y. (Youqing Yuan), H.S., Y.Y. (Youming Yuan), J.W. and Z.Y.; Investigation, Y.W., Y.C., K.W., Y.Y. (Youqing Yuan), H.S., Y.Y. (Youming Yuan), J.W. and Z.Y.; Resources, Y.Y. (Youqing Yuan), Y.Y. (Youming Yuan) and A.W.; Data curation, Y.W., Y.C., K.W., Y.Y. (Youqing Yuan), H.S., Y.Y. (Youming Yuan), J.W. and Z.Y.; Writing—original draft preparation, Y.W. and Y.C.; Writing—review and editing, D.D. and A.W.; Visualization, Y.W.; Supervision, D.D. and A.W.; Project administration, D.D. and A.W.; Funding acquisition, A.W. All authors have read and agreed to the published version of the manuscript. Funding This research was funded by Hunan Punosai Biotechnology Co., Ltd., Grant No. XCZX-2024533, and the Hunan Provincial Natural Science Foundation of China, Grant No. 2020JJ4041. Institutional Review Board Statement The animal study protocol was approved by the Biomedical Research Ethics Committee of Hunan Agricultural University (HUNAU, Changsha, China) (Approval No. 2026-33, 9 March 2026). All animal procedures were conducted in accordance with the national guidelines for the care and use of laboratory animals in China and were designed to minimize animal suffering. Informed Consent Statement Not applicable. Data Availability Statement All data supporting the findings of this study are included within the article. Additional raw data are available from the corresponding author upon reasonable request. Acknowledgments The authors would like to thank the graduate students at Hunan Agricultural University for their assistance in animal care and sample collection. Conflicts of Interest The authors declare no other competing interests. 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Wang, Y.; Chen, Y.; Wang, K.; Yuan, Y.; Sun, H.; Yuan, Y.; Wang, J.; Yang, Z.; Yang, Y.; Wang, N.; et al. Identification of Conserved Cross-Reactive B-Cell Epitopes in CPV1 and CPV2 L1 Proteins with Vaccine Potential. Vaccines 2026, 14, 512. https://doi.org/10.3390/vaccines14060512 Wang Y, Chen Y, Wang K, Yuan Y, Sun H, Yuan Y, Wang J, Yang Z, Yang Y, Wang N, et al. Identification of Conserved Cross-Reactive B-Cell Epitopes in CPV1 and CPV2 L1 Proteins with Vaccine Potential. Vaccines. 2026; 14(6):512. https://doi.org/10.3390/vaccines14060512 Wang, Yuge, Yingyi Chen, Kaixin Wang, Youqing Yuan, Haojie Sun, Youming Yuan, Jixian Wang, Zhicai Yang, Yi Yang, Naidong Wang, and et al. 2026. "Identification of Conserved Cross-Reactive B-Cell Epitopes in CPV1 and CPV2 L1 Proteins with Vaccine Potential" Vaccines 14, no. 6: 512. https://doi.org/10.3390/vaccines14060512 Wang, Y., Chen, Y., Wang, K., Yuan, Y., Sun, H., Yuan, Y., Wang, J., Yang, Z., Yang, Y., Wang, N., Duan, D., & Wang, A. (2026). Identification of Conserved Cross-Reactive B-Cell Epitopes in CPV1 and CPV2 L1 Proteins with Vaccine Potential. Vaccines, 14(6), 512. https://doi.org/10.3390/vaccines14060512
