A randomized, double-blind phase I clinical trial of two recombinant dimeric RBD COVID-19 vaccine candidates: Safety, reactogenicity and immunogenicity.

BACKGROUND: The Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein is the target for many COVID-19 vaccines. Here we report results for phase I clinical trial of two COVID-19 vaccine candidates based on recombinant dimeric RBD (d-RBD). METHODS: We performed a randomized, double-blind, phase I clinical trial in the National Centre of Toxicology in Havana. Sixty Cuban volunteers aged 19-59 years were randomized into three groups (20 subjects each): 1) FINLAY-FR-1 (50 µg d-RBD plus outer membrane vesicles from N. meningitidis); 2) FINLAY-FR-1A-50 (50 µg d-RBD, three doses); 3) FINLAY-FR-1A-25 (25 µg d-RDB, three doses). The FINLAY-FR-1 group was randomly divided to receive a third dose of the same vaccine candidate (homologous schedule) or FINLAY-FR-1A-50 (heterologous schedule). The primary outcomes were safety and reactogenicity. The secondary outcome was vaccine immunogenicity. Humoral response at baseline and following each vaccination was evaluated using live-virus neutralization test, anti-RBD IgG ELISA and in-vitro neutralization test of RBD:hACE2 interaction. RESULTS: Most adverse events were of mild intensity (63.5%), solicited (58.8%), and local (61.8%); 69.4% with causal association with vaccination. Serious adverse events were not found. The FINLAY-FR-1 group reported more subjects with adverse events than the other two groups. After the third dose, anti-RBD seroconversion was 100%, 94.4% and 90% for the FINLAY-FR-1, FINLAY-FR-1A-50 and FINLAY-FR-1A-25 respectively. The in-vitro inhibition of RBD:hACE2 interaction increased after the second dose in all formulations. The geometric mean neutralizing titres after the third dose rose significantly in the group vaccinated with FINLAY-FR-1 with respect to the other formulations and the COVID-19 Convalescent Serum Panel. No differences were found between FINLAY-FR-1 homologous or heterologous schedules. CONCLUSIONS: Vaccine candidates were safe and immunogenic, and induced live-virus neutralizing antibodies against SARS-CoV-2. The highest values were obtained when outer membrane vesicles were used as adjuvant. TRIAL REGISTRY: https://rpcec.sld.cu/en/trials/RPCEC00000338-En.

El inicio de relaciones coitales en estudiantes de preuniversitario / The start of sexual relations among senior high school students

Introducción: internacionalmente resulta de interés mejorar la calidad de vida de hombres y mujeres, por ello es importante la detección temprana de problemas de salud como aquellos relacionados con la sexualidad. Objetivo: describir los aspectos principales relacionados con el inicio de relaciones coitales en adolescentes.Métodos: investigación observacional, descriptiva, transversal. El universo lo constituyeron los alumnos y alumnas de tres escuelas de enseñanza preuniversitaria; la muestra estuvo representada por 450 estudiantes seleccionados de forma estratificada e intencional, 150 jóvenes por centro; 50 de cada año académico comprendido entre los 15 y 18 años de edad. Se aplicó una encuesta validada por el Ministerio de Educación en el 2005.Resultados: se constató que en los muchachos las relaciones coitales se iniciaron más frecuentemente a los 14 años, cuando cursaban la secundaria básica; y a los 15 años en las muchachas, en el preuniversitario. El empleo de preservativo en la primera relación coital, los chicos lo refirieron en el 55,2 por ciento de los casos y las chicas solo constituyeron el 49,8 por ciento. Como lugares para su primera relación coital refirieron la casa de uno de los miembros de la pareja y las escuelas becadas. La novia o el novio fueron por lo general las personas con quienes se iniciaron sexualmente. Los adolescentes buscan con mayor frecuencia la satisfacción sexual, la compañía y la confianza; mientras que las adolescentes buscan apoyo, afecto, comprensión y confianza. Conclusiones: se evidenció la persistencia de patrones socialmente heredados relacionados con estereotipos de género, poca percepción de riesgo de contraer infecciones de transmisión sexual y tendencia a inicio de relaciones coitales en etapas tempranas de la adolescencia, sobre todo en los muchachos(AU)

Introduction: improvement of the quality of life of men and women is a topic of worldwide interest. Hence the importance of early detection of health problems such as those related to sexuality. Objective: describe the main aspects of the start of sexual relations among adolescents. Methods: cross-sectional observational descriptive study. The study universe was male and female students from three senior high schools. The sample consisted of 450 students selected in an intentional, stratified manner: 150 students from each institution; 50 from each school year, age 15-18. Data collection was based on a survey validated by the Ministry of Education in the year 2005. Results: it was found that boys often start their sexual life at age 14, while in junior high school, whereas girls start at age 15, while in senior high school. 55.2 percent of boys reported wearing a condom in their first sexual intercourse, whereas girls constituted a mere 49.8 percent. The home of either partner or the boarding school they attended were reported as the places for the first sexual experience. Subjects generally reported to have had their first sexual experience with their boyfriend or girlfriend. Boys most often search for sexual satisfaction, company and trust, whereas girls try to find support, affection, understanding and trust. Conclusions: persistence of inherited social patterns related to gender, a poor perception of the risk of acquiring a sexually transmitted disease, and the tendency to start sexual relations early in adolescence, mainly boys, were all made evident by the study(AU)

El inicio de relaciones coitales en estudiantes de preuniversitario / The start of sexual relations among senior high school students

Introducción: internacionalmente resulta de interés mejorar la calidad de vida de hombres y mujeres, por ello es importante la detección temprana de problemas de salud como aquellos relacionados con la sexualidad. Objetivo: describir los aspectos principales relacionados con el inicio de relaciones coitales en adolescentes. Métodos: investigación observacional, descriptiva, transversal. El universo lo constituyeron los alumnos y alumnas de tres escuelas de enseñanza preuniversitaria; la muestra estuvo representada por 450 estudiantes seleccionados de forma estratificada e intencional, 150 jóvenes por centro; 50 de cada año académico comprendido entre los 15 y 18 años de edad. Se aplicó una encuesta validada por el Ministerio de Educación en el 2005. Resultados: se constató que en los muchachos las relaciones coitales se iniciaron más frecuentemente a los 14 años, cuando cursaban la secundaria básica; y a los 15 años en las muchachas, en el preuniversitario. El empleo de preservativo en la primera relación coital, los chicos lo refirieron en el 55,2 % de los casos y las chicas solo constituyeron el 49,8 %. Como lugares para su primera relación coital refirieron la casa de uno de los miembros de la pareja y las escuelas becadas. La novia o el novio fueron por lo general las personas con quienes se iniciaron sexualmente. Los adolescentes buscan con mayor frecuencia la satisfacción sexual, la compañía y la confianza; mientras que las adolescentes buscan apoyo, afecto, comprensión y confianza. Conclusiones: se evidenció la persistencia de patrones socialmente heredados relacionados con estereotipos de género, poca percepción de riesgo de contraer infecciones de transmisión sexual y tendencia a inicio de relaciones coitales en etapas tempranas de la adolescencia, sobre todo en los muchachos.

Introduction: improvement of the quality of life of men and women is a topic of worldwide interest. Hence the importance of early detection of health problems such as those related to sexuality. Objective: describe the main aspects of the start of sexual relations among adolescents. Methods: cross-sectional observational descriptive study. The study universe was male and female students from three senior high schools. The sample consisted of 450 students selected in an intentional, stratified manner: 150 students from each institution; 50 from each school year, age 15-18. Data collection was based on a survey validated by the Ministry of Education in the year 2005. Results: it was found that boys often start their sexual life at age 14, while in junior high school, whereas girls start at age 15, while in senior high school. 55.2 % of boys reported wearing a condom in their first sexual intercourse, whereas girls constituted a mere 49.8 %. The home of either partner or the boarding school they attended were reported as the places for the first sexual experience. Subjects generally reported to have had their first sexual experience with their boyfriend or girlfriend. Boys most often search for sexual satisfaction, company and trust, whereas girls try to find support, affection, understanding and trust. Conclusions: persistence of inherited social patterns related to gender, a poor perception of the risk of acquiring a sexually transmitted disease, and the tendency to start sexual relations early in adolescence, mainly boys, were all made evident by the study.