Background: Newcastle disease virus (NDV) is a highly contagious and economically devastating pathogen affecting poultry worldwide, leading to significant losses in the poultry industry. Despite existing vaccines, outbreaks continue to occur, highlighting the need for more effective vaccination strategies. Developing a multi-epitopic peptide vaccine offers a promising approach to enhance protection against NDV. Objectives: Here, we aimed to design and evaluate a multi-epitopic vaccine against NDV using molecular dynamics (MD) simulation. Methodology: We retrieved NDV sequences for the fusion (F) protein and hemagglutinin–neuraminidase (HN) protein. Subsequently, B-cell and T-cell epitopes were predicted. The top potential epitopes were utilized to design the vaccine construct, which was subsequently docked against chicken TLR4 and MHC1 receptors to assess the immunological response. The resulting docked complex underwent a 1 microsecond (1000 ns) MD simulation. For experimental evaluation, the vaccine’s efficacy was assessed in mice and chickens using a controlled study design, where animals were randomly divided into groups receiving either a local ND vaccine or the peptide vaccine or a control treatment. Results: The 40 amino acid peptide vaccine demonstrated strong binding affinity and stability within the TLR4 and MHC1 receptor–peptide complexes. The root mean square deviation of peptide vaccine and TLR4 receptor showed rapid stabilization after an initial repositioning. The root mean square fluctuation revealed relatively low fluctuations (below 3 Å) for the TLR4 receptor, while the peptide exhibited higher fluctuations. The overall binding energy of the peptide vaccine with TLR4 and MHC1 receptors amounted to −15.7 kcal·mol⁻¹ and −36.8 kcal·mol⁻¹, respectively. For experimental evaluations in mice and chicken, the peptide vaccine was synthesized using services of GeneScript Biotech^® (Singapore) PTE Limited. Experimental evaluations showed a significant immune response in both mice and chickens, with the vaccine eliciting robust antibody production, as evidenced by increasing HI titers over time. Statistical analysis was performed using an independent t-test with Type-II error to compare the groups, calculating the p-values to determine the significance of the immune response between different groups. Conclusions: Multi-epitopic peptide vaccine has demonstrated a good immunological response in natural hosts.

| In the present study, we investigated the prevalence of Salmonella in various parts of table eggs collected from various union councils of Peshawar, Khyber Pakhtunkhwa Pakistan. For this purpose, 200 egg samples were collected. The culturing of Salmonella from egg shell and their contents was carried out according to ISO guidelines for Salmonella isolation. A total of twenty-two (22) eggs were positive for Salmonella species. The antibiotic susceptibility testing revealed that Salmonella isolates were resistant to ampicillin, amoxicillin/clavulanic acid, cefotaxime, and kanamycin while isolates were susceptible to chloramphenicol, gentamicin, kanamycin and streptomycin. These positive samples were further investigated and confirmed through PCR by targeting serovars specific genes i.e rfbJ, fliC, fljB for S. Typhimurium and ST11, SPV, SefA for S. Enteritidis . The prevalence of Salmonella was found to be 22 (11%), out of which 17 (77.27%) isolates were S. Enteritidis and 5 (22.73%) isolates were found to be S. Typhimurium as confirmed through PCR. The presence of infectious Salmonella in table eggs in Peshawar presents a serious public health threat and should be monitored on routine basis for the presence of Salmonella.