Farmacovigilancia intensiva de vacunas SOBERANA®02 y Soberana®Plus en población pediátrica en el Centro de Inmunología Molecular

Las vacunas SOBERANA®02 y SOBERANA® Plus contra el coronavirus tipo 2 causante del síndrome respiratorio agudo severo, recibieron autorización de uso en emergencia por la autoridad reguladora de Cuba, y de inmediato aconteció una campaña de vacunación masiva en población pediátrica, lo que devino en una inminente movilización de centros de vacunación y vigilancia de sus eventos adversos. El Centro de Inmunología Molecular realizó un estudio de farmacovigilancia intensiva que evalúo el cumplimiento del esquema heterólogo con ambas vacunas, su seguridad y la incidencia de casos positivos a COVID-19 en niños y adolescentes después de completar el esquema de inmunización. Desde el 15 de septiembre al 31 de diciembre del 2021, participaron 529 sujetos entre 2 y 18 años de edad, de ambos sexos, sin antecedentes de infección por coronavirus tipo 2 del síndrome respiratorio agudo severo, procedentes de 35 municipios y 12 provincias cubanas, quienes recibieron vacuna SOBERANA®02 (dos dosis) y SOBERANA®Plus (una dosis). Se realizó vigilancia de eventos adversos hasta 30 días después de la última dosis recibida. Se consultó la plataforma informática nacional Higia Andariego para identificar los casos positivos al virus del síndrome respiratorio agudo severo coronavirus 2, hasta 3 meses de haber completado la vacunación. El 98,5% de los participantes completó el esquema de vacunación y en el 6,6% se notificó algún evento adverso con relación consistente a la vacunación. Predominaron las reacciones locales (dolor, eritema, inflamación), sobre las reacciones sistémicas (fatiga y febrícula), de intensidad ligera o moderada. Se logró un elevado cumplimiento del esquema de inmunización, con un perfil de seguridad favorable, los sujetos con esquema completo de inmunización no enfermaron de COVID-19

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

Open-label phase I/II clinical trial of SARS-CoV-2 receptor binding domain-tetanus toxoid conjugate vaccine (FINLAY-FR-2) in combination with receptor binding domain-protein vaccine (FINLAY-FR-1A) in children

Objectives: To evaluate a heterologous vaccination scheme in children 3-18 years old (y/o) combining two SARS-CoV-2r- receptor binding domain (RBD)protein vaccines. Methods: A phase I/II open-label, adaptive, and multicenter trial evaluated the safety and immunogenicity of two doses of FINLAY-FR-2 (subsequently called SOBERANA 02) and the third heterologous dose of FINLAY-FR-1A (subsequently called SOBERANA Plus) in 350 children 3-18 y/o in Havana Cuba. Primary outcomes were safety (phase I) and safety/immunogenicity (phase II) measured by anti-RBD immunoglobulin (Ig)G enzyme-linked immunoassay (ELISA), molecular and live-virus neutralization titers, and specific T-cells response. A comparison with adult immunogenicity and predictions of efficacy were made based on immunological results. Results: Local pain was the unique adverse event with frequency >10%, and none was serious neither severe. Two doses of FINLAY-FR-2 elicited a humoral immune response similar to natural infection; the third dose with FINLAY-FR-1A increased the response in all children, similar to that achieved in vaccinated young adults. The geometric mean (GMT) neutralizing titer was 173.8 (95% confidence interval [CI] 131.7; 229.5) vs Alpha, 142 (95% CI 101.3; 198.9) vs Delta, 24.8 (95% CI 16.8; 36.6) vs Beta and 99.2 (95% CI 67.8; 145.4) vs Omicron. Conclusion: The heterologous scheme was safe and immunogenic in children 3-18 y/o. Trial registry: https://rpcec.sld.cu/trials/RPCEC0000037