Vacunas contra rotavirus: estado actual y tendencias futuras

Antes de la introducción de las vacunas contra el rotavirus en 2006, este patógeno era considerado la principal causa de gastroenteritis entre los niños menores de cinco años de edad, de todo el mundo. Las vacunas son una estrategia fundamental para proteger a los niños de la gastroenteritis severa por rotavirus. Actualmente existen dos vacunas comerciales disponibles Rotarix® y RotaTeq® y su aplicación está teniendo un impacto en la reducción en las hospitalizaciones y consultas, sin embargo, para los países pobres los costos para sostener un programa de inmunización son relativamente elevados. Existe además la preocupación de que la vacuna conlleve a la selección y difusión de cepas nuevas y antigénicamente diferentes que traigan consigo la disminución de eficacia de la vacuna. Para solventar estos aspectos los productores trabajan en la búsqueda de nuevas vacunas como es la vacuna de origen indio ROTAVAC®. Las autoridades sanitarias de varios países han implementado programas de vigilancia en hospitales centinelas para seguir la hospitalización debido a la gastroenteritis por rotavirus y conducir estudios para evaluar la efectividad e impacto de la vacuna

Generation of a murine monoclonal antibody to capsular polysaccharide Vi from Salmonella Typhi

The conventional hybridoma technology has enabled the development of monoclonal antibodies (Mabs) against many antigens. Mabs have several applications in the field of basic research, diagnosis, immunotherapy and vaccine manufacturing processes. Mabs-producing hybridomas against the capsular polysaccharide from Salmonella Typhi were obtained, after intraperitoneal immunization of BALB/c mice with 10 µg of capsular polysaccharide Vi conjugated to diphtheria toxoid, and subsequent fusion of lymphocytes isolated of the spleen and myeloma cells SP2/O. A Mab was selected, partially characterized, and named as 4G3E11. The isotype of this Mab was IgG1. It was proved by means of a sandwich ELISA that the 4G3E11 Mab reacts with different concentrations of polysaccharide in samples of the vax-TyVi® vaccine. The Mab obtained in this research could be useful as reagent for the detection and quantitation of polysaccharide Vi in typhoid vaccines

OMV-based vaccine formulations against Shiga toxin producing Escherichia coli strains are both protective in mice and immunogenic in calves

Fil: Fingermann, Matias. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Avila, Lucía. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: De Marco, Maria Belén. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Vázquez, Luciana. ANLIS Dr.C.G.Malbrán. Unidad Operativa Centro de Contención Biológica; Argentina.Fil: Di Biase, Darío Nicolás. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Müller, Andrea Verónica. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Lescano, Mirta. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Dokmetjian, José Christian. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Fernández Castillo, Sonsire. Instituto Finlay, La Habana; Cuba.Fil: Pérez Quiñoy, José Luis. Instituto Finlay, La Habana; Cuba.Strains of Shiga toxin-producing Escherichia coli (STEC) can cause the severe Hemolytic Uremic Syndrome (HUS). Shiga toxins are protein toxins that bind and kill microvascular cells, damaging vital organs. No specific therapeutics or vaccines have been licensed for use in humans yet. The most common route of infection is by consumption of dairy or farm products contaminated with STEC. Domestic cattle colonized by STEC strains represent the main reservoir, and thus a source of contamination. Outer Membrane Vesicles (OMV) obtained after detergent treatment of gram-negative bacteria have been used over the past decades for producing many licensed vaccines. These nanoparticles are not only multi-antigenic in nature but also potent immunopotentiators and immunomodulators. Formulations based on chemical-inactivated OMV (OMVi) obtained from a virulent STEC strain (O157:H7 serotype) were found to protect against pathogenicity in a murine model and to be immunogenic in calves. These initial studies suggest that STEC-derived OMV has a potential for the formulation of both human and veterinary vaccines

Real-world effectiveness of the heterologous SOBERANA-02 and SOBERANA-Plus vaccine scheme in 2–11 years-old children during the SARS-CoV-2 Omicron wave in Cuba: a longitudinal case-population studyResearch in context

Summary: Background: Increased pediatric COVID-19 occurrence due to the SARS-CoV-2 Omicron variant has raised concerns about the effectiveness of existing vaccines. The protection provided by the SOBERANA-02-Plus vaccination scheme against this variant has not yet been studied. We aimed to evaluate the scheme's effectiveness against symptomatic Omicron infection and severe disease in children. Methods: In September 2021, Cuba implemented a mass pediatric immunization with the heterologous SOBERANA-02-Plus scheme: 2 doses of conjugated SOBERANA-02 followed by a heterologous SOBERANA-Plus dose. By December, before the Omicron outbreak, 95.4% of 2–18 years-old had been fully immunized. During the entire Omicron wave, we conducted a nationwide longitudinal post-vaccination case-population study to evaluate the real-world effectiveness of the SOBERANA-02-Plus scheme against symptomatic infection and severe disease in children without previous SARS-CoV-2 infection. The identification of COVID-19 cases relied on surveillance through first line services, which refer clinical suspects to pediatric hospitals where they are diagnosed based on a positive RT-PCR test. We defined the Incidence Rate ratio (IRR) as IRvaccinated age group/IRunvaccinated 1-year-old and calculated vaccine effectiveness as VE = (1—IRR)∗100%. 24 months of age being the ‘eligible for vaccination’ cut-off, we used a regression discontinuity approach to estimate effectiveness by contrasting incidence in all unvaccinated 1-year-old versus vaccinated 2-years-old. Estimates in the vaccinated 3–11 years-old are reported from a descriptive perspective. Findings: We included 1,098,817 fully vaccinated 2–11 years-old and 98,342 not vaccinated 1-year-old children. During the 24-week Omicron wave, there were 7003/26,241,176 person-weeks symptomatic COVID-19 infections in the vaccinated group (38.2 per 105 person-weeks in 2-years-old and 25.5 per 105 person-weeks in 3–11 years-old) against 3577/2,312,273 (154.7 per 105 person-weeks) in the unvaccinated group. The observed overall vaccine effectiveness against symptomatic infection was 75.3% (95% CI, 73.5–77.0%) in 2-years-old children, and 83.5% (95% CI, 82.8–84.2%) in 3–11 years-old. It was somewhat lower during Omicron BA.1 then during Omicron BA.2 variant circulation, which took place 1–3 and 4–6 months after the end of the vaccination campaign. The effectiveness against severe symptomatic disease was 100.0% (95% CI not estimated) and 94.6% (95% CI, 82.0–98.6%) in the respective age groups. No child death from COVID-19 was observed. Interpretation: Immunization of 2–11 years-old with the SOBERANA-02-Plus scheme provided strong protection against symptomatic and severe disease caused by the Omicron variant, which was sustained during the six months post-vaccination follow-up. Our results contrast with the observations in previous real-world vaccine effectiveness studies in children, which might be explained by the type of immunity a conjugated protein-based vaccine induces and the vaccination strategy used. Funding: National Fund for Science and Technology (FONCI-CITMA-Cuba)

Diseño, desarrollo y evaluación preclínica de SOBERANA®02: una vacuna cubana contra COVID-19

International audienc

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