Comparative Immune Response after Vaccination with SOBERANA® 02 and SOBERANA® plus Heterologous Scheme and Natural Infection in Young Children.

(1) Background: In children, SARS-CoV-2 infection is mostly accompanied by mild COVID-19 symptoms. However, multisystem inflammatory syndrome (MIS-C) and long-term sequelae are often severe complications. Therefore, the protection of the pediatric population against SARS-CoV-2 with effective vaccines is particularly important. Here, we compare the humoral and cellular immune responses elicited in children (n = 15, aged 5-11 years) vaccinated with the RBD-based vaccines SOBERANA® 02 and SOBERANA® Plus combined in a heterologous scheme with those from children (n = 10, aged 4-11 years) who recovered from mild symptomatic COVID-19. (2) Methods: Blood samples were taken 14 days after the last dose for vaccinated children and 45-60 days after the infection diagnosis for COVID-19 recovered children. Anti-RBD IgG and ACE2-RBD inhibition were assessed by ELISA; IgA, cytokines, and cytotoxic-related proteins were determined by multiplex assays. Total B and T cell subpopulations and IFN-γ release were measured by multiparametric flow cytometry using a large panel of antibodies after in vitro stimulation with S1 peptides. (3) Results: Significant higher levels of specific anti-RBD IgG and IgA and ACE2-RBD inhibition capacity were found in vaccinated children in comparison to COVID-19 recovered children. Th1-like and Th2-like CD4+ T cells were also significantly higher in vaccinated subjects. IFN-γ secretion was higher in central memory CD4+ T cells of COVID-19 recovered children, but no differences between both groups were found in the CD4+ and CD8+ T cell effector, terminal effector, and naïve T cell subpopulations. In contrast to low levels of IL-4, high levels of IL-2, IL-6, IFN-γ, and IL-10 suggest a predominant Th1 cell polarization. Cytotoxic-related proteins granzyme A and B, perforin, and granulin were also found in the supernatant after S1 stimulation in both vaccinated and recovered children. (4) Conclusions: Vaccination with the heterologous scheme of SOBERANA® 02/SOBERANA® Plus induces a stronger antibody and cellular immune response compared to natural infections in young children.

Estudio de intervención con SOBERANA® en los trabajadores del Centro Nacional de Biopreparados / Intervention study with SOBERANA® in the workers of the Centro Nacional de Biopreparados

Se presentan los resultados del estudio de intervención realizado en el Centro Nacional de Biopreparados, empresa de BioCubaFarma. La investigación fue promovida por el Instituto Finlay de Vacunas, con el objetivo de evaluar los efectos directos e indirectos de la vacunación anti SARS-CoV-2 con un esquema heterólogo 2P+1: dos dosis de SOBERANA®02 más una dosis de SOBERANA®Plus con 28 días entre ellas, en cohortes poblacionales de riesgo de infección, enfermedad y dispersión de la epidemia. Fueron evaluados 1.007 sujetos, incluyéndose inicialmente 924. De ellos, el 97,62 por ciento recibió el esquema completo de vacunación. Posteriormente se incluyeron 21 convalecientes de COVID-19 con al menos dos meses del alta clínica, que recibieron una única dosis de SOBERANA®Plus. La seguridad de las vacunas se evalúo mediante la identificación y clasificación de los eventos adversos por farmacovigilancia activa y pasiva. Se registraron un total de 482 eventos adversos, en su mayoría por farmacovigilancia pasiva, de intensidad leve y de causalidad A1 (relacionados). No ocurrieron eventos adversos graves relacionados. Se realizó cuantificación de IgG anti SARS-CoV-2 a 100 individuos y el 68 por ciento tuvo una respuesta mayor o igual de 50 UA/mL, siendo estos sujetos nueve años menores que los de respuesta menor. Hasta los tres meses de concluida la intervención, 64 vacunados fueron diagnosticados con COVID-19 y ninguno de ellos estuvo grave o falleció. Se evidenció un perfil de seguridad muy favorable de SOBERANA® e indicios de efectividad en la prevención de formas graves y mortalidad por COVID-19(AU)

The results of an intervention study performanced at the Centro Nacional de Biopreparados, a company of BioCubaFarma, are presented. The research was promoted by the Finlay Vaccine Institute, with the aim of evaluating the direct and indirect effects of vaccination against SARS-CoV-2, with a heterologous 2P + 1 scheme: two doses of SOBERANA®02 plus one dose of SOBERANA®Plus with 28 days between them; in population cohorts at risk of infection, disease and spread of the epidemic. A quantity of 1,007 subjects were evaluated and 924 were initially included. Of these, 97.62 percent received the complete vaccination schedule. Subsequently, 21 convalescents of COVID-19 with at least two months of clinical discharge were included, who received a single dose of SOBERANA®Plus. The safety of the vaccine was evaluated by identifying and classifying adverse events by active and passive pharmacovigilance. A total of 482 adverse events were recorded, mostly due to passive pharmacovigilance, mild intensity and A1 causality (related). No related serious adverse events occurred. IgG anti SARS-CoV-2 was quantified in 100 individuals, and 68 percent had a response greater than or equal to 50 IU/mL, these subjects being nine years younger than those with a lower response. Up to three months after the intervention, 64 vaccinated people were diagnosed with COVID-19 and none of them were seriously ill or died. A very favorable safety profile of SOBERANA® and indications of effectiveness in preventing severe forms and mortality from COVID-19 were evidenced(AU)

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.