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/RPCEC00000374.

Safety and immunogenicity of anti-SARS-CoV-2 heterologous scheme with SOBERANA 02 and SOBERANA Plus vaccines: Phase IIb clinical trial in adults.

BACKGROUND: SOBERANA 02 has been evaluated in phase I and IIa studies comparing homologous versus heterologous schedule (this one, including SOBERANA Plus). Here, we report results of immunogenicity, safety, and reactogenicity of SOBERANA 02 in a two- or three-dose heterologous scheme in adults. METHOD: Phase IIb was a parallel, multicenter, adaptive, double-blind, randomized, and placebo-controlled trial. Subjects (n = 810) aged 19-80 years were randomized to receive two doses of SARS-CoV-2 RBD conjugated to tetanus toxoid (SOBERANA 02) and a third dose of dimeric RBD (SOBERANA Plus) 28 days apart; two production batches of active ingredients of SOBERANA 02 were evaluated. Primary outcome was the percentage of seroconverted subjects with ≥4-fold the anti-RBD immunoglobulin G (IgG) concentration. Secondary outcomes were safety, reactogenicity, and neutralizing antibodies. FINDINGS: Seroconversion rate in vaccinees was 76.3% after two doses and 96.8% after the third dose of SOBERANA Plus (7.3% in the placebo group). Neutralizing IgG antibodies were detected against D614G and variants of concern (VOCs) Alpha, Beta, Delta, and Omicron. Specific, functional antibodies were detected 7-8 months after the third dose. The frequency of serious adverse events (AEs) associated with vaccination was very low (0.1%). Local pain was the most frequent AE. CONCLUSIONS: Two doses of SOBERANA 02 were safe and immunogenic in adults. The heterologous combination with SOBERANA Plus increased neutralizing antibodies, detectable 7-8 months after the third dose. TRIAL REGISTRY: https://rpcec.sld.cu/trials/RPCEC00000347 FUNDING: This work was supported by Finlay Vaccine Institute, BioCubaFarma, and the Fondo Nacional de Ciencia y Técnica (FONCI-CITMA-Cuba, contract 2020-20).

Safety and immunogenicity of the FINLAY-FR-1A vaccine in COVID-19 convalescent participants: an open-label phase 2a and double-blind, randomised, placebo-controlled, phase 2b, seamless, clinical trial.

BACKGROUND: A phase 1, clinical trial to evaluate FINLAY-FR-1A vaccine in COVID-19 convalescent individuals was completed. Here, we report results of the phase 2, clinical trial. METHODS: We studied 450 convalescent participants with a history of asymptomatic, mild, or moderate COVID-19 at the National Institute of Hematology and Immunology and the National Centre for Sexual Education in Havana, Cuba. The study included adults aged 19-78 years who had recovered from COVID-19 and had had a negative PCR test at least 2 months before the initiation of the study. Phase 2 was done sequentially in two stages. The first stage to assess safety comprised an open, non-controlled phase 2a study in participants aged 60-78 years who received a single dose of the FINLAY-FR-1A vaccine (50 µg of recombinant dimeric receptor binding domain [RBD]). The second stage comprised the placebo-controlled, double-blind, phase 2b trial in participants aged 19-78 years, where participants were randomly assigned (4:1) into two groups: an experimental group vaccinated with a single dose of the FINLAY-FR-1A vaccine, and a control (placebo) group injected with vaccine excipient. The primary outcomes were safety, evaluated 28 days after vaccination by the occurrence of serious adverse events in all participants, and successful immune response, assessed by neutralising antibody ELISA, and defined as half-maximal surrogate virus neutralisation titres of 250 or more. Secondary endpoints included vaccine immunogenicity assessed by ELISA anti-RBD and live-virus neutralisation test. All randomly assigned participants were included in the safety analysis (safety population), and immunogenicity was evaluated in participants without study interruptions (per-protocol population). The trial is registered with the Cuban Public Registry of Clinical Trials, RPCEC00000366-En and WHO-ICTRP and is complete. FINDINGS: From April 9, 2021, to April 17, 2021, 663 COVID-19 convalescent participants were enrolled in the study; 213 participants did not meet the selection criteria and 450 volunteers were recruited. 20 participants aged 60-78 years were included in the open, single-group, phase 2a study and 430 participants were randomly assigned to the experimental (n=344) or control groups (n=86) in the phase 2b study of participants aged 19-78 years. 19 (95%) of 20 phase 2a volunteers achieved a successful immune response after vaccination. No vaccine-associated serious adverse events were reported in the whole study population. Minor adverse events were found, the most common being pain at the injection site (105 [29%] of 364 in the intervention group; 13 [15%] of 86 in the placebo group). A successful immune response was found in 289 (81%) of 358 participants 28 days after vaccination. The vaccine elicited a greater than 31-times increase in anti-RBD-IgG antibodies compared with prevaccination rates, and the seroconversion rate was 302 (84%) of 358 on day 28 after vaccination; the geometric mean titres of live-virus neutralisation test increased from 15·4 (95% CI 10·3-23·2) to 400·3 (272·4-588·1) and high response was found against alpha, beta, and delta variants of concern. INTERPRETATION: A single dose of the FINLAY-FR-1A vaccine against SARS-CoV-2 strengthened the pre-existing natural immunity, with excellent safety profile. FUNDING: Cuba's Ministry of Science, Technology, and Environment.

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.

Safety, tolerability, and immunogenicity of a SARS-CoV-2 recombinant spike RBD protein vaccine: A randomised, double-blind, placebo-controlled, phase 1-2 clinical trial (ABDALA Study).

Background: Multiple vaccine candidates against COVID-19 are currently being evaluated. We evaluate the safety and immunogenicity protein of a novel SARS-CoV-2 virus receptor-binding domain (RBD) vaccine. Methods: A phase 1-2, randomised, double-blind, placebo-controlled trial was carried out in "Saturnino Lora" Hospital, Santiago de Cuba, Cuba. Subjects (healthy or those with controlled chronic diseases) aged between 19 and 80 years, who gave written informed consent were eligible. Subjects were randomly assigned (1:1:1, in blocks) to three groups: placebo, 25 µg and 50 µg RBD vaccine (Abdala). The product was administered intramuscularly, 0·5 mL in the deltoid region. During the first phase, two immunization schedules were studied: 0-14-28 days (short) and 0-28-56 days (long). In phase 2, only the short schedule was evaluated. The organoleptic characteristics and presentations of vaccine and placebo were identical. All participants (subjects, clinical researchers, statisticians, laboratory technicians, and monitors) remained masked during the study period. The main endpoints were safety and the proportion of subjects with seroconversion of anti-RBD IgG antibodies, analysed by intention to treat and per protocol, respectively. The trial is registered with the Cuban Public Registry of Clinical Trials, RPCEC00000346. Findings: Between Dec 7, 2020, and Feb 9, 2021, 792 subjects were included; 132 (66 in each vaccination schedule, divided into 22 for each group) in phase 1, and 660 (220 in each group plus 66 from the short scheme of phase 1) in phase 2. The product was well tolerated. No severe adverse events were reported. During phase 1, the incidence of adverse events in the 25 µg, 50 µg, and placebo arms for the short schedule were 6/22 (27·3%), 6/22 (27·3%), 3/22 (13·6%), respectively, and for the long schedule were 8/22 (36·4%), 9/22 (40·9%), 4/22 (18·2%), respectively. In phase 2, adverse reactions were reported by 53/242 (21·9%), 75/242 (31·0%) and 41/242 (16·9%) participants in the 25 µg, 50 µg, and placebo group, respectively. Adverse reactions were minimal, mostly mild, and from the injection site, which resolved in the first 24-48 hours. In phase 1, seroconversion at day 56 was seen in 95·2% of the participants (20/21) in the 50 µg group, 81% (17/21) in the 25 µg group, and none in the placebo group (0/22). For the long schedule, seroconversion at day 70 was seen in 100% of the participants (21/21) in the 50 µg group, 94·7% (18/19) in the 25 µg group, and none in the placebo group (0/22). In phase 2, seroconversion of anti-RBD IgG antibodies at day 56 was seen in 89·2% of the participants in the 50 µg group (214/240; 95% CI 84·5-92·82), 77·7% in the 25 µg group (185/238; 72·0-82·9) and 4·6% in the placebo group (11/239; 2·3-8·1). Compared with the placebo arm, the differences in the proportion of participants with seroconversion were 73·1% (95% CI 66·8-79·5) and 84·6% (79·4-89·7) in the 25 µg and 50 µg groups, respectively. The seroconversion rate in the 50 µg group was significantly higher than in the 25 µg group (p=0·0012). Interpretation: The Abdala vaccine was safe, well tolerated, and induced humoral immune responses against SARS-CoV-2. These results, in the context of the emergency COVID-19 pandemic, support the 50 µg dose, applied in a 0-14-28 days schedule, for further clinical trials to confirm vaccine efficacy. Funding: Centre for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba.

Evaluación de estuches de PCR-tiempo real para detección de virus del papiloma humano de alto riesgo / Evaluation of real-time PCR kits to detect high-risk human papillomavirus

RESUMEN Introducción: El empleo de técnicas moleculares para el diagnóstico de virus del papiloma humano de alto riesgo oncogénico (VPH-AR) es crucial para la detección precoz del cáncer cervicouterino. Objetivo: Evaluar el desempeño analítico de dos estuches de PCR-tiempo real, comercializados por el Centro de Inmunoensayo de Cuba, para detectar VPH-AR. Métodos: Se utilizaron dos paneles de ADN de muestras cervicouterinas: uno con 150 muestras, para validar el estuche SUMASIGNAL HPV 16/18, el proceso de extracción de ADN y su utilidad como prueba cuantitativa, y otro con 163 muestras para evaluar el estuche HPV 13+2. Se determinó la utilidad clínica del estuche HPV 13+2 en 55 muestras cervicovaginales autocolectadas. Se calcularon los indicadores de desempeño analítico de ambos estuches con respecto a pruebas de referencia. Resultados: Los indicadores de desempeño para SUMASIGNAL HPV 16/18 fueron excelentes (> 95 %), concordancia 96 %, índice kappa=0,93 [0,85-1,01]. La extracción de ADN mostró 100 % de especificidad clínica y analítica y 95 % de sensibilidad analítica. Se obtuvo buena correlación con la prueba de referencia cuantitativa (r = + 0,688). El estuche HPV 13+2 tuvo especificidad y sensibilidad clínicas del 100 %, la especificidad analítica fue del 84 % debido a reactividad cruzada con otros VPH-AR. Su aplicación clínica reveló alta frecuencia de infección (41,8 %): 23,6 % con VPH-AR, particularmente en mujeres jóvenes (50 %). La muestra autocolectada resultó útil (100 %). Conclusión: Los ensayos evaluados mostraron altos estándares de calidad, lo que permitiría su uso con una cobertura nacional en una plataforma tecnológica disponible para todo el país.

ABSTRACT Introduction: The use of molecular techniques for the diagnosis of high oncogenic risk human papillomavirus (hrHPV) is crucial for the early detection of cervical cancer. Objective: To evaluate the analytical performance of two real-time PCR kits, commercialized by the Cuban Immunoassay Center, to detect hrHPV. Methods: Two DNA panels from cervical samples were used: one with 150 samples to validate the SUMASIGNAL HPV 16/18 kit, the DNA extraction process and its usefulness as a quantitative test; and another with 163 samples to evaluate the HPV 13+2 kit. The clinical utility of the HPV 13+2 kit was determined in 55 self-collected cervicovaginal samples. The analytical performance indicators of both kits were calculated with respect to reference tests. Results: Performance indicators for SUMASIGNAL HPV 16/18 were excellent (>95%), concordance 96%, kappa index=0.93 [0.85-1.01]. DNA extraction showed 100% clinical and analytical specificity and 95% analytical sensitivity. Good correlation was obtained with the quantitative reference test (r = + 0.688). The HPV 13+2 kit had 100% clinical specificity and sensitivity, analytical specificity was 84% due to cross-reactivity with other hrHPVs. Its clinical application revealed a high frequency of infection (41.8%): 23.6% with hrHPV, particularly in young women (50%). The self-collected sample was viable (100%). Conclusion: The assays evaluated showed high quality standards, which would allow their use with national coverage in a technological platform available for the whole country.