Salmonella enterica is an important foodborne pathogen. Commercial poultry are the main reservoirs of Salmonella enterica, leading to the contamination of food and outbreaks in humans. The vaccination of chickens is one of the most important strategies to reduce the number of Salmonella in poultry farms. Unfortunately, commercial vaccines have not been fully effective in controlling the spread and do not contain all the Salmonella serovars that circulate on farms. In this study, we evaluate a new, cochleate-based, trivalent injectable vaccine against S. Enteritidis, S. Typhimurium and S. Infantis, describing the vaccine security, capacity to induce specific anti-Salmonella serovar IgY and the gene expression of immune markers related to CD4 and CD8 T-cell-mediated immunity. Efficacy was evaluated through oral challenges performed separately for each Salmonella serotype. The efficacy and safety of the trivalent vaccine was proven under controlled conditions. The vaccine has no local or systemic reactions or adverse effects on poultry performance related to the vaccine. The vaccine provided significantly increased serum IgY titer levels, significantly reduced Salmonella CFU/g present in the cecum and an increased CD4+/CD8+ ratio in vaccinated animals when challenged with S. Infantis, S. Enteritidis and S. Typhimurium. These results indicate that this new trivalent vaccine does not generate adverse effects in poultry and produces an increase in neutralizing antibodies against the three Salmonella serovars.

Canine chronic inflammatory enteropathy (CIE) is one of the most common chronic gastrointestinal diseases affecting dogs worldwide. Genetic and environmental factors, as well as intestinal microbiota and dysregulated host immune responses, participate in this multifactorial disease. Despite advances explaining the immunological and molecular mechanisms involved in CIE development, the exact pathogenesis is still unknown. This review compiles the latest reports and advances that describe the main molecular and cellular mechanisms of both the innate and adaptive immune responses involved in canine CIE pathogenesis. Future studies should focus research on the characterization of the immunopathogenesis of canine CIE in order to advance the establishment of biomarkers and molecular targets of diagnostic, prognostic, or therapeutic utility.

Salmonid rickettsial septicaemia (SRS) is a contagious disease caused by Piscirickettsia salmonis, an intracellular bacterium. SRS causes an estimated economic loss of $700 million USD to the Chilean industry annually. Vaccination and antibiotic therapy are the primary prophylactic and control measures used against SRS. Unfortunately, commercially available SRS vaccines have not been shown to have a significant effect on reducing mortality. Most vaccines contain whole inactivated bacteria which results in decreased efficacy due to the limited ability of the vaccine to evoke a cellular mediated immune response that can eliminate the pathogen or infected cells. In addition, SRS vaccine efficacy has been evaluated primarily with Salmo salar (Atlantic salmon). Vaccine studies using Oncorhynchus mykiss (rainbow trout) are scarce, despite SRS being the leading cause of infectious death for this species. In this study, we evaluate an injectable vaccine based on P. salmonis proteoliposome; describing the vaccine security profile, capacity to induce specific anti-P. salmonis IgM and gene expression of immune markers related to T CD8 cell-mediated immunity. Efficacy was determined by experimental challenge with P. salmonis intraperitoneally. Our findings indicate that a P. salmonis proteoliposome-based vaccine is able to protect O. mykiss against challenge with a P. salmonis Chilean isolate and causes a specific antibody response. The transcriptional profile suggests that the vaccine is capable of inducing cellular immunity. This study provides new insights into O. mykiss protection and the immune response induced by a P. salmonis proteoliposome-based vaccine.

Context: The new generation of immunoenhancers will have to offer solutions to each clinical and technological limitation that currently exists. This innovative context requires periodic technological surveillance by the veterinary biopharmaceutical industry to anticipate technological changes and predict future competitive advantages. Aims: To evaluate the current status, scientific trends, and technological projections in the use of veterinary immunological adjuvants for productive and companion species in the period 2015 and 2021. Methods: The bibliometric analysis included scientific articles on adjuvants in veterinary medicine published in English in 2015–2021 and indexed on the Scopus and Web of Science platforms. All relevant records retrieved between 2015 and 2022 were grouped using the EndNote bibliographic manager, while the analysis of the relational metric indicator was performed and viewed by VOSviewer®. Instead, data on the main commercial veterinary vaccine adjuvants in 2022 were collected from the official websites of 20 veterinary vaccine manufacturers with experience in the market. Results: The academy dedicated 68.2% of its production to disseminating articles with original experimental results with 73.6% being novel notifications about adjuvants of natural, microbial and nanotechnological origin. Industrial production mainly used monoadjuvation (86.9%), inorganic salts adjuvants (48.1%), particularly aluminum hydroxide (43.0%), and classical technology (89.2%) to produce their commercial formulations. Ruminants, swines, and poultry dominated both sectors, with ruminants being the main protagonist. Conclusions: The new scientific knowledge will not have a significant impact on the veterinary pharmaceutical industry in the short term and the hegemonic continuity of traditional adjuvants, in particular aluminum hydroxide, is expected.

Background/Objectives: The ongoing evolution of SARS-CoV-2 has highlighted the limitations of parenteral vaccines in preventing viral transmission, largely due to their failure to elicit robust mucosal immunity. Methods: Here, we evaluated an intranasal (IN) vaccine formulation consisting of recombinant receptor-binding domain (RBD) adsorbed onto human probiotic Bacillus subtilis DG101 spores. Results: In BALB/c mice, IN spore-RBD immunization induced strong systemic and mucosal humoral responses, including elevated specific IgG, IgM, and IgA levels in serum, bronchoalveolar lavage fluid (BALF), nasal-associated lymphoid tissue (NALT), and saliva. It further promoted mucosal B cell and T cell memory, along with a Th1/Tc1-skewed T cell response, characterized by increased IFN-γ-expressing CD4⁺ and CD8⁺ T cells in the lungs. Conclusions: All in all, these findings highlight the potential of intranasal vaccines adjuvanted with probiotic B. subtilis spores in inducing sterilizing immunity and limiting SARS-CoV-2 transmission.

Background. Mucosal vaccination offers the possibility of establishing immune protection directly at portals of pathogen entry, but its development remains constrained by biological, technological, and implementation barriers. Objective. To integrate the major challenges limiting mucosal vaccination within a common framework and examine emerging strategies capable of addressing several of these barriers simultaneously. Results and Discussion. We consider six interconnected challenges: incomplete recognition of the determinant role of adjuvants; scarcity of safe and accessible mucosal adjuvants; the need to overcome mucosal tolerance while preserving tissue homeostasis; dependence on coldchain logistics; reliance on multidose immunization schedules to achieve protective immunity; and limited breadth of vaccine-induced cross-reactive protection. To better capture the complexity of modern vaccine platforms, we discuss expand adjuvant activity as exogenous, self-adjuvanting, or endogenous according to the origin of the immunostimulatory signal. Particular emphasis is placed on proteoliposome- and cochleate-based systems and probiotic Bacillus subtilis spores as multifunctional platforms combining antigen delivery with intrinsic immunostimulatory properties. Preclinical studies support their capacity to induce systemic IgG, mucosal secretory IgA, cellular responses, and memory response, while their heat resistance may facilitate the development of more thermostable formulations. We also discuss the Single Time Vaccination Strategy as an approach to combined-route immunization and consider glycans and other microbial structures as potential contributors to antigen-specific and cross-reactive mucosal responses. Conclusions. Future mucosal vaccine development should consider adjuvants as tools for coordinated antigen delivery, innate sensing, immune programming with polarization activity, and mucosal memory rather than solely as immune potentiators and delivery system. Probiotic spores, cochleates, and combined-route strategies provide promising examples of this integrated approach, although their translational value will require rigorous demonstration of formulation stability, mechanisms of action, safety, protective breadth, and clinical efficacy.