Safety and immunogenicity of anti-SARS CoV-2 vaccine SOBERANA 02 in homologous or heterologous scheme: Open label phase I and phase IIa clinical trials.

BACKGROUND: SOBERANA 02 is a COVID-19 vaccine based on SARS-CoV-2 recombinant RBD conjugated to tetanus toxoid (TT). SOBERANA Plus antigen is dimeric-RBD. Here we report safety and immunogenicity from phase I and IIa clinical trials using two-doses of SOBERANA 02 and three-doses (homologous) or heterologous (with SOBERANA Plus) protocols. METHOD: We performed an open-label, sequential and adaptive phase I to evaluate safety and explore the immunogenicity of SOBERANA 02 in two formulations (15 or 25 µg RBD-conjugated to 20 µg of TT) in 40 subjects, 19-59-years-old. Phase IIa was open-label including 100 volunteers 19-80-years, receiving two doses of SOBERANA 02-25 µg. In both trials, half of volunteers were selected to receive a third dose of the corresponding SOBERANA 02 and half received a heterologous dose of SOBERANA Plus. Primary outcome was safety. The secondary outcome was immunogenicity evaluated by anti-RBD IgG ELISA, molecular neutralization of RBD:hACE2 interaction, live-virus-neutralization and specific T-cells response. RESULTS: The most frequent adverse event (AE) was local pain, other AEs had frequencies ≤ 5%. No serious related-AEs were reported. Phase IIa confirmed the safety in 60 to 80-years-old subjects. In phase-I SOBERANA 02-25 µg elicited higher immune response than SOBERANA 02-15 µg and progressed to phase IIa. Phase IIa results confirmed the immunogenicity of SOBERANA 02-25 µg even in 60-80-years. Two doses of SOBERANA02-25 µg elicited an immune response similar to that of the Cuban Convalescent Serum Panel and it was higher after the homologous and heterologous third doses. The heterologous scheme showed a higher immunological response. Anti-RBD IgG neutralized the delta variant in molecular assay, with a 2.5-fold reduction compared to D614G neutralization. CONCLUSIONS: SOBERANA 02 was safe and immunogenic in persons aged 19-80 years, eliciting neutralizing antibodies and specific T-cell response. Highest immune responses were obtained in the heterologous three doses protocol. TRIAL REGISTRY: https://rpcec.sld.cu/trials/RPCEC00000340, https://rpcec.sld.cu/trials/RPCEC00000347.

Ensayo clínico de reto, para evaluar una cepa candidata a vacuna contra el cólera / Challenge clinical trial for evaluation of a vaccine candidate strain against cholera

INTRODUCCIÓN: la cepa atenuada 638 Vibrio cholerae O1 El Tor, Ogawa, ha demostrado ser bien tolerada e inmunogénica por vía oral en estudios realizados en voluntarios sanos. OBJETIVO: se evaluó la protección conferida contra el cólera, en un ensayo clínico de reto, para el escalado tecnológico y farmacéutico de este candidato vacunal como ingrediente activo a escala industrial. MÉTODOS: en el estudio participaron 21 voluntarios sanos, 12 de ellos recibieron el candidato vacunal, y 9 ingirieron un placebo; 28 d después, todos recibieron una dosis infectante de una cepa virulenta de V.cholerae. RESULTADOS: la diarrea se registró en 7 de los 9 placebos, mientras que ninguno de los voluntarios vacunados presentó diarrea. Los voluntarios placebos del grupo sanguíneo O, tuvieron diarreas con mayor frecuencia e intensidad. Todos los voluntarios en el grupo placebo excretaron V. cholerae mientras que solo 3 (25 por ciento) de los 12 vacunados la excretaron. CONCLUSIONES: en este modelo de ensayo de reto, la cepa 638 demostró proteger contra la diarrea producida por una cepa virulenta de V. cholerae (AU)

INTRODUCTION: live attenuated oral Vibrio cholerae O1 El Tor, Ogawa strain 638 has demonstrated to be well tolerated and immunogenic when administrated orally in studies carried out in healthy volunteers. OBJECTIVE: to evaluate the protection against cholera infection in a challenge clinical trial, for the technological and pharmaceutical scale-up of this vaccinal candidate as active ingredient at industrial level. METHOD: a total of 21 healthy volunteers were involved in this trial; the vaccine candidate was administered to 12 of them and the remaining nine were given the placebo. Twenty eight days later, all of them received an infective dose of a V. cholerae virulent strain. RESULTS: diarrheas were observed in 7 out of 9 placebos whereas not a single vaccinated volunteer showed diarrheas. More frequent and intense loose stools were found in the placebo volunteers with O-blood group. All volunteers in he placebo group excreted V. cholerae, but only three (25 percent) out of the 12 vaccinated volunteers did so. CONCLUSION: in this challenge clinical trial model, the 638 strain proved to protect people against the diarrhea caused by a virulent V. cholerae strain (AU)

Ensayo clínico de reto, para evaluar una cepa candidata a vacuna contra el cólera / Challenge clinical trial for evaluation of a vaccine candidate strain against cholera

INTRODUCCIÓN: la cepa atenuada 638 Vibrio cholerae O1 El Tor, Ogawa, ha demostrado ser bien tolerada e inmunogénica por vía oral en estudios realizados en voluntarios sanos. OBJETIVO: se evaluó la protección conferida contra el cólera, en un ensayo clínico de reto, para el escalado tecnológico y farmacéutico de este candidato vacunal como ingrediente activo a escala industrial. MÉTODOS: en el estudio participaron 21 voluntarios sanos, 12 de ellos recibieron el candidato vacunal, y 9 ingirieron un placebo; 28 d después, todos recibieron una dosis infectante de una cepa virulenta de V.cholerae. RESULTADOS: la diarrea se registró en 7 de los 9 placebos, mientras que ninguno de los voluntarios vacunados presentó diarrea. Los voluntarios placebos del grupo sanguíneo O, tuvieron diarreas con mayor frecuencia e intensidad. Todos los voluntarios en el grupo placebo excretaron V. cholerae mientras que solo 3 (25 por ciento) de los 12 vacunados la excretaron. CONCLUSIONES: en este modelo de ensayo de reto, la cepa 638 demostró proteger contra la diarrea producida por una cepa virulenta de V. cholerae (AU)

INTRODUCTION: live attenuated oral Vibrio cholerae O1 El Tor, Ogawa strain 638 has demonstrated to be well tolerated and immunogenic when administrated orally in studies carried out in healthy volunteers. OBJECTIVE: to evaluate the protection against cholera infection in a challenge clinical trial, for the technological and pharmaceutical scale-up of this vaccinal candidate as active ingredient at industrial level. METHOD: a total of 21 healthy volunteers were involved in this trial; the vaccine candidate was administered to 12 of them and the remaining nine were given the placebo. Twenty eight days later, all of them received an infective dose of a V. cholerae virulent strain. RESULTS: diarrheas were observed in 7 out of 9 placebos whereas not a single vaccinated volunteer showed diarrheas. More frequent and intense loose stools were found in the placebo volunteers with O-blood group. All volunteers in he placebo group excreted V. cholerae, but only three (25 percent) out of the 12 vaccinated volunteers did so. CONCLUSION: in this challenge clinical trial model, the 638 strain proved to protect people against the diarrhea caused by a virulent V. cholerae strain (AU)

Ensayo clínico de reto, para evaluar una cepa candidata a vacuna contra el cólera / Challenge clinical trial for evaluation of a vaccine candidate strain against cholera

INTRODUCCIÓN: la cepa atenuada 638 Vibrio cholerae O1 El Tor, Ogawa, ha demostrado ser bien tolerada e inmunogénica por vía oral en estudios realizados en voluntarios sanos. OBJETIVO: se evaluó la protección conferida contra el cólera, en un ensayo clínico de reto, para el escalado tecnológico y farmacéutico de este candidato vacunal como ingrediente activo a escala industrial. MÉTODOS: en el estudio participaron 21 voluntarios sanos, 12 de ellos recibieron el candidato vacunal, y 9 ingirieron un placebo; 28 d después, todos recibieron una dosis infectante de una cepa virulenta de V.cholerae. RESULTADOS: la diarrea se registró en 7 de los 9 placebos, mientras que ninguno de los voluntarios vacunados presentó diarrea. Los voluntarios placebos del grupo sanguíneo O, tuvieron diarreas con mayor frecuencia e intensidad. Todos los voluntarios en el grupo placebo excretaron V. cholerae mientras que solo 3 (25 por ciento) de los 12 vacunados la excretaron. CONCLUSIONES: en este modelo de ensayo de reto, la cepa 638 demostró proteger contra la diarrea producida por una cepa virulenta de V. cholerae.

INTRODUCTION: live attenuated oral Vibrio cholerae O1 El Tor, Ogawa strain 638 has demonstrated to be well tolerated and immunogenic when administrated orally in studies carried out in healthy volunteers. OBJECTIVE: to evaluate the protection against cholera infection in a challenge clinical trial, for the technological and pharmaceutical scale-up of this vaccinal candidate as active ingredient at industrial level. METHOD: a total of 21 healthy volunteers were involved in this trial; the vaccine candidate was administered to 12 of them and the remaining nine were given the placebo. Twenty eight days later, all of them received an infective dose of a V. cholerae virulent strain. RESULTS: diarrheas were observed in 7 out of 9 placebos whereas not a single vaccinated volunteer showed diarrheas. More frequent and intense loose stools were found in the placebo volunteers with O-blood group. All volunteers in he placebo group excreted V. cholerae, but only three (25 percent) out of the 12 vaccinated volunteers did so. CONCLUSION: in this challenge clinical trial model, the 638 strain proved to protect people against the diarrhea caused by a virulent V. cholerae strain.

[Challenge clinical trial for evaluation of a vaccine candidate strain against cholera]. / Ensayo clínico de reto, para evaluar una cepa candidata a vacuna contra el cólera.

INTRODUCTION: live attenuated oral Vibrio cholerae Ol El Tor, Ogawa strain 638 has demonstrated to be well tolerated and immunogenic when administrated orally in studies carried out in healthy volunteers. OBJECTIVES: to evaluate the protection against cholera infection in a challenge clinical trial, for the technological and pharmaceutical scale-up of this vaccinal candidate as active ingredient at industrial level. METHODS: a total of 21 healthy volunteers were involved in this trial; the vaccine candidate was administered to 12 of them and the remaining nine were given the placebo. Twenty eight days later, all of them received an infective dose of a V. cholerae virulent strain. RESULTS: diarrheas were observed in 7 out of 9 placebos whereas not a single vaccinated volunteer showed diarrheas. More frequent and intense loose stools were found in the placebo volunteers with O-blood group. All volunteers in he placebo group excreted V. cholerae, but only three (25%) out of the 12 vaccinated volunteers did so. CONCLUSION: in this challenge clinical trial model, the 638 strain proved to protect people against the diarrhea caused by a virulent V. cholerae strain.

Evaluación clínica de un candidato vacunal basado en la cepa atenuada 638 Vibrio cholerae O1 El Tor Ogawa / Clinical evaluation of a vaccine candidate based on the attenuated strain 638 Vibrio cholerae O1 El Tor Ogawa

Un proceso tecnológico desarrollado en Cuba con la cepa atenuada 638 Vibrio cholerae O1 El Tor Ogawa, permitió obtener un candidato vacunal oral contra el cólera. En los ensayos clínicos realizados con poblaciones diferentes, una no endémica de cólera (Cuba) y otraendémica (Mozambique), mostró que no se registraron eventos adversos graves; la seroconversión de anticuerpos vibriocidas fue de un 100 por cientoen Cuba y de 97,47 por ciento en Mozambique. Se concluye que este candidato vacunal fue seguro, bien tolerado e inmunogénico en ambaspoblaciones(AU)

A technological process developed in Cuba with the attenuated strain 638 Vibrio cholerae O1 El Tor Ogawa allowed to obtain an oral vaccinecandidate against cholera. Clinical trials conducted with different populations, a cholera non-endemic pupulation (Cuba) and an endemic population (Mozambique) showed no serious adverse events registered; seroconversion of vibriocidal antibodies was 100 percent in Cuba and 97,47 percent in Mozambique. It is concluded that this vaccine candidate is safe, well tolerated and immunogenic in both populations(AU)