Repeat-dose and local tolerance toxicity of SARS-CoV-2 FINLAY-FR-02 vaccine candidate in Sprague Dawley rats.

This study evaluates safety of FINLAY-FR-02, a vaccine candidate against SARS-CoV-2 based on the recombinant receptor binding domain conjugated to tetanus toxoid, in a preclinical, repeat-dose toxicity and local tolerance study. Sprague Dawley rats were randomly allocated to three experimental groups: control (receiving physiological saline solution); placebo (receiving all vaccine components except antigens) and vaccine group (receiving three doses of the vaccine candidate, 37.5 µg of RBD) administered intramuscularly in hind limbs at 24 h intervals during three days. We evaluated physiological condition, pain, food and water consumption, body temperature, dermal irritability, injection site temperature and inflammation, immunological response, blood chemistry, relative organ weight, histopathology and immunotoxicology. The product was well tolerated; no clinically relevant changes, pain, local effects or adverse systemic toxicological changes or deaths were observed. These preliminary results permitted the Cuban regulatory authorities to authorize clinical trials in humans.

Ensayo de inmunogenicidad y toxicidad aguda del candidato vacunal contra el cólera vax-COLER® / Immunogenicity and acute toxicity assay of the vaccine candidate against cholera vax-COLER®

Para el control y prevención del cólera humano se han llevado a cabo diferentes estrategias, entre las cuales, la vacunación es una de las medidas más eficaces. La evaluación preclínica de candidatos vacunales requiere de la demostración de la seguridad de los mismos, para lo cual los estudios toxicológicos son determinantes, al ser obligatorios y altamente regulados. Este estudio tuvo como objetivo demostrar la relevancia de las ratas Sprague Dawley como biomodelo a través de su respuesta inmunológica al candidato vacunal contra el cólera, vax-COLER®, utilizando la técnica de determinación de anticuerpos vibriocidas. Además, evaluar los efectos toxicológicos locales y sistémicos por la administración de una dosis de vax-COLER® a través de la evaluación de síntomas, del consumo de agua y alimentos, el peso corporal y estudios anatomopatológicos. La vacuna vax-COLER® resultó inmunogénica y no evidenció síntomas ni muertes, no hubo cambios en el peso corporal y los consumos de agua y alimentos se comportaron de forma similar entre todos los grupos. Los estudios anatomopatológicos solo mostraron cambios a nivel histológico en los ganglios linfáticos mesentéricos y placas de Peyer de los animales vacunados, con presencia de hiperplasia de los folículos secundarios subcapsulares, hallazgo que difirió significativamente con el resto de los grupos. Se concluye que la vacuna vax-COLER® es inmunogénica en ratas Sprague Dawley, demostrando la relevancia del biomodelo para la evaluación de la seguridad preclínica y que la aplicación de una dosis no produjo efectos tóxicos agudos generales ni locales(AU)

Different strategies have been carried out for the control and prevention of human cholera. Vaccination is one of the most effective strategies. Preclinical evaluation of vaccines needs to prove their safety; whereby toxicological studies are decisive. They are mandatory and highly regulated. This study was aimed to demonstrate the relevance of Sprague Dawley rats as a biomodel, through the immunological response to vax-COLER® cholera vaccine, using the technique of determination of vibriocidal antibodies. In addition, local and systemic toxicological effects were evaluated after administration of a dose of vax-COLER®; through the evaluation of symptoms, water and food consumption, body weight and anatomopathological studies. The vax-COLER® vaccine was immunogenic and showed no symptoms or deaths. No changes in body weight were detected, and food and water consumption were similar among all groups. The anatomopathological studies showed histological changes in the mesenteric lymph nodes and Peyer's patches of the vaccinated animals, with hyperplasia of the subcapsular secondary follicles, finding that differed significantly from the rest of the groups. It is concluded that vax-COLER® vaccine is immunogenic in Sprague-Dawley rats, demonstrating the relevance of the biomodel for the evaluation of preclinical safety, as well as that the application of a single dose did not produce acute general or local toxic effects(AU)

Evaluación de formulaciones inmunoterapéuticas experimentales en el modelo hibrido murino de Reaccion del Injerto contra el Hospedador / Evaluation of experimental immunotherapeutic formulations in the hybrid murine model of Graft-versus-Host Reaction

Introducción: La Enfermedad del Injerto Contra el Hospedador es la complicación más frecuente de los Trasplantes de Células Madre Hematopoyéticas y de todos los trasplantes que contengan células inmunocompetentes alogénicas, el 100 por ciento la padecen y cerca del 30 por ciento mueren por su causa; una proporción alta de casos son esteroide-refractarios, asimismo otras medidas inmunosupresoras modernas fracasan. En los campos de la Inmunoterapia y la Vaccinología también existe una escasez preocupante de inmunomoduladores de origen biológico potentes, efectivos, seguros y de amplio espectro. Existe un modelo híbrido murino de gran utilidad metodológica para estudios experimentales. Objetivo: Evaluar dos formulaciones novedosas de origen biotecnológico, una de ellas inmunopotenciadora y otra inmunosupresora, desarrolladas como cocleatos. Material y Métodos: Mediante Microscopia Electrónica y RT-PCR se caracterizaron las formulaciones como nanopartículas y su capacidad de regular la expresión del ARNm de linfoquinas definitorias de sus perfiles, respectivamente. Empleando el modelo de Enfermedad del Injerto Contra el Hospedador en ratón híbrido F1 (CBAxC57BL), se evaluó su carácter inmunomodulador in vivo . Resultados: Partiendo de los proteoliposomas de Neisseria meningitidis, se obtuvieron dos formulaciones en forma de cocleatos, ambas con diámetros de partícula inferior a 100nm. La Formulación 1mostró un perfil proinflamatorio con potente capacidad de aumentar el IFNγ y el TNFα y potenció el Índice de Bazo hasta 2,05 en el modelo EICH con p=0,0002. La Formulación 2 mostró un perfil supresor-regulatorio con potente capacidad de aumentar la IL-10 y el TGFβ y además de suprimir la producción de TNFα. En el modelo usado, esta formulación, suprimió el Índice de Bazo de manera dosis dependiente y con alta significación estadística. Se corroboró el conocido perfil de seguridad y ausencia de reactogenicidad de ambas formulaciones. Conclusiones: Ambas formulaciones tienen potencial aplicación en los campos de la terapia de Enfermedad del Injerto Contra el Hospedador en otras patologías y en Vaccinología. Los resultados obtenidos en el presente trabajo fundamentan la conveniencia de continuar el desarrollo farmacéutico y completar la preclínica de ambas formulaciones(AU)

Introduction: Graft-versus-host disease is the most frequent complication of Hematopoietic Stem Cell Transplants and all transplants containing allogeneic immunocompetent cells; 100 percent of patients suffer from this complication and about 30 percent die for this particular cause. A high proportion of cases are steroid-refractory; likewise, other modern immunosuppressive measures fail. In the fields of Immunotherapy and Vaccinology, there is also a worrying shortage of powerful, effective, safe and broad spectrum immunomodulators of biological origin. There is a hybrid murine model of great methodological utility for experimental studies. Objective: To evaluate two novel formulations of biotechnological origin: an immunopotentiator formulation and an immunosuppressive one, which were developed as cochleates. Material and Methods: The formulations assayed by Electron Microscopy and RT-PCR were characterized as nanoparticles and for their capacity to regulate lymphokine mRNA expression profile, respectively. The immunomodulatory character was evaluated in vivo using Graft-versus-host disease in (CBAxC57BL) F1 hybrid mice. Results: Starting from the proteoliposomes derived from Neisseria meningitides, two cochleate formulations were obtained, both with particle diameters below 100 nm. Formulation 1 showed a proinflammatory profile with potent capacity to increase IFNγ and TNFα, and potentiated the Spleen Index up to 2.05 in the GVDH model with p = 0.0002. Formulation 2 showed a suppressor/regulatory profile with potent capacity to increase IL-10 and TGFβ and suppress the production of TNFα. In the model used, this formulation suppressed the Spleen Index in a dose-dependent manner with high statistical significance. The known safety profile and absence of reactogenicity of both formulations was corroborated. Conclusions: Both formulations have potential application in the fields of GVHD therapy and other pathologies as well as in Vaccinology. The results obtained in the present work suggest the usefulness to continue with the pharmaceutical development and complete the preclinical studies of both formulations(AU)

Remote induction of cellular immune response in mice by anti-meningococcal nanocochleates - nanoproteoliposomes.

New adjuvant formulations, based on proteoliposomes <40 nm and cochleates <100 nm, without Al(OH)3 adjuvant, were evaluated regarding their ability to generate Th1 immune response through a Delayed -Type Hypersensitivity Test, at the mouse model, by using a Neisseria meningitidis B protein complex as antigen. The formulations were administered by intramuscular (IM) (2 inoculations - at baseline and after 14 days) and intranasal (IN) (3 inoculations at 7 days) immunization pathways. All IM immunized groups were able to induce similar response to these formulations as well as to VA-MENGOC-BC® vaccine - containing Al(OH)3 adjuvant (used as positive control of the trial). In all groups, the induced inflammation (IP) rate was statistically higher than in the negative control group (CN) (p < 0.05). Immunogenicity, measured by HSR and CD4+ lymphocyte increase was equivalent to the control vaccine and most important, granuloma reactogenicity at the site of injection was eliminated, fact demonstrated by histological study. All groups of animals immunized by IN route showed HSR reactions and statistically significant differences with respect to the CN group. However, IP values were lower, with statistical differences (p < 0.05) for the same adjuvant formulation IM administered, except the AIF2-nCh formulation that generated statistically similar induction (p > 0.05) by both immunization pathways, suggesting it to be the best candidate for the next IN trial. Proteoliposome and cochleate formulations tested were able to mount potent Th-1 immune response, equivalent to the original vaccine formulation, with the advantage of less reactogenicity in the site of the injection, caused by the toxicity of Al(OH)3 adjuvant gel.

Estudio de tolerancia local de la vacuna antimeningocóccica VA-MENGOC-BC® en ratas Sprague Dawley. Evaluación a los 24 y 36 meses en estante / Local tolerance study of the VA-MENGOC-BC® antimeningococcal vaccine in Sprague Dawley rats. Evaluation at 24 and 36 months of shelf

La meningitis meningocóccica continua siendo un problema de salud en diferentes países y para la prevención de esta enfermedad se han obtenido diferentes vacunas. La vacuna VA-MENGOC-BC® ha constituido ser eficaz y segura en la prevención de la meningitis meningocóccica contra los serogrupos B y C. Esta ha demostrado buena estabilidad en el tiempo sin cambiar su calidad como producto; fue conservada a estante durante 24 y 36 meses a temperaturas de 4 a 8 °C. Se evaluó su posible potencial toxicológico a través de un estudio de tolerancia local en ratas Sprague Dawley para extender su vida útil. Los animales inmunizados se observaron diariamente para evaluar síntomas locales y sistémicos de toxicidad. Se realizaron evaluaciones del peso corporal, consumo de agua y alimento, termometría, musculometría e irritabilidad dérmica por el método de Draize. Se realizaron estudios anatomopatológicos periódicos para observar posibles efectos adversos. No se observaron síntomas de toxicidad ni muertes. No se encontraron diferencias entre los grupos experimentales en cuanto al peso corporal, el consumo de agua y de alimentos, no se evidenció fiebre, ni irritabilidad local. Anatomopatológicamente a nivel del punto de inoculación se observaron procesos granulomatosos de tipo macrofágicos característicos en las vacunas que contienen hidróxido de aluminio. Estos resultados permitieron concluir que la vacuna VA-MENGOC-BC® que permaneció en estante durante 24 y 36 meses no evidenció efectos adversos locales, ni sistémicos en las ratas(AU)

Meningococcal meningitis continues to be a health problem in different countries and different vaccines have been obtained for the prevention of this disease. VA-MENGOC-BC® vaccine has been effective and safe in the prevention of meningococcal meningitis against serogroups B and C. This has shown good stability over time without changing its quality as a product; it was stored on a shelf for 24 and 36 months at temperatures of 4 to 8 °C. Their possible toxicological potential was evaluated through a local tolerance study in Sprague Dawley rats. Immunized animals were observed daily to evaluate local and systemic toxicity symptoms. Body weight, water and feed intake, thermometry, musculometry were performed and dermal irritability by the Draize method. Anatomopathological studies to observe possible adverse effects were made. No symptoms of toxicity or deaths were observed. No differences were found between the experimental groups in terms of body weight, water and food consumption, no fever or local irritability was evident. Anatomopathologically no lesions of diagnostic value were observed, at the site of inoculation, granulomatous processes of macrophagic type characteristic in vaccines containing aluminum hydroxide were observed. These results allowed us to conclude that the VA-MENGOC-BC® vaccine that remained on the shelf for 24 and 36 months did not show any local or systemic effects in rats(AU)