Background: Nipah virus (NiV), a zoonotic paramyxovirus with high case fatality and pandemic potential, remains without a licensed vaccine for humans to date. Although there has been progress in vaccine development, it remains limited, and peptide vaccines have rarely been validated in vivo. Methods: Here, we report the rational antigen selection, synthesis, and preliminary immunogenicity evaluation of NiV fusion glycoprotein (NiV-F)-derived linear peptides as vaccine candidates. Candidate epitopes were identified by in silico, and a total of 18 B- and T-cell epitope-derived peptides were shortlisted for synthesis and antigenicity validation by ELISA. Results: Antigenicity evaluation showed that 9 of the synthesized peptides have A_450nm of over 1 (8 from the F11 group, A_450nm: 1.13–3.6; 1 from the F18 group, A_450nm: 1.51), with the peptide constructs F11-3 (A_450nm: 3.5) and F11-4 (A_450nm: 3.6) showing the highest antigenicity. Interestingly, peptides from F11 with amidation increased antibody binding (F11-4-NH2, A_450nm: 3.05; F11-4-9mer-1-NH2, A_450nm: 0.87). The lead peptide candidates, F11-3 and F11-4, were subsequently used for the immunization experiment, and mouse sera were assessed against their homologous peptide antigens or recombinant NiV-F protein. ELISA result showed detectable antibody reactivity against their homologous antigen for the intramuscular (IM) F11-3 vaccinated group (A_450nm: 0.30 ± 0.35), whereas increased binding was observed for both IM-administered F11-3 (A_450nm: 1.62 ± 0.97) and F11-4 (A_450nm: 2.0 ± 0.77) against NiV-F protein, albeit without statistical significance compared to the negative control (NC, p > 0.05), and were markedly lower compared to mice immunized with NiV-F recombinant protein (PC, p < 0.01), underscoring the need for further optimization procedures. Conclusions: Collectively, these results support an exploratory antigen discovery and prioritization framework for NiV-F-derived peptide candidates and provide a foundation for future studies aimed at optimizing immunogenicity and evaluating protective relevance in appropriate preclinical models.

Despite the growth in South Korea’s goat industry, epidemiological data on goat coccidiosis—an intestinal disease caused by Eimeria spp., causing diarrhea and productivity losses, particularly in kids—remain limited. In 2025, fecal samples from 67 farms across 12 regions in Gyeongsangnam-do were analyzed for oocyst detection, oocysts per gram (OPG) quantification, and cytochrome c oxidase subunit I (COI) sequencing. Farm-level prevalence was high at 83.6% (56/67; range, 66.7–100%), with a mean OPG of 1136 (range: 250–7033) among positive samples. Morphologically, the observed oocysts resembled E. christenseni, E. arloingi, and E. hirci. COI-based BLAST analysis showed high identity with E. christenseni and E. arloingi, whereas phylogenetic analysis revealed affinities extending to E. hirci and sequences from cattle (E. bovis, E. zuernii) and sheep (E. ahsata). However, substantial COI heterogeneity, pooled sampling, and potential preferential amplification during Sanger sequencing limited confident species assignment. Here, findings demonstrate farm-level Eimeria detection but do not establish clinical or subclinical coccidiosis since clinical status was not systematically assessed. Nevertheless, these data establish a useful epidemiological and genetic baseline and highlight the need for multi-locus analysis (18S rRNA, internal transcribed spacer [ITS], and COI) to improve species-level resolution for surveillance and control strategies.

One of the diseases causing the greatest economic damage to the poultry industry is coccidiosis. Effective in vitro screening platforms can accelerate research on coccidiosis control by identifying and prioritizing interventions for subsequent validation in more resource- and labor-intensive in vivo studies. Consequently, increasing the invasion rate of Eimeria sporozoites is considered a crucial step in elucidating the process of parasitic infection and defense mechanisms. This study investigated the invasion rate of E. tenella sporozoites upon the supplementation of whole-cell lysates and quantified the sporozoite load using microscopic counting and an absolute quantitative real-time PCR assay targeting the internal transcribed spacer 1 (ITS-1) region of the nuclear ribosomal DNA of E. tenella. Compared to cell culture media with invasion rates of 13.9–34.4%, the whole-cell lysate supplementation significantly enhanced sporozoite invasion to 38.7–81.3% over time (p < 0.05). These findings enable the efficient use of the large quantities of sporozoites required for repeated experiments and also reduce the need for the difficult and time-consuming process of extracting sporozoites from sporulated oocysts. This result is expected to be highly beneficial for cell-based experiments utilizing Eimeria sporozoites.