Immunogenicity and safety of Biological E's CORBEVAX™ vaccine compared to COVISHIELD™ (ChAdOx1 nCoV-19) vaccine studied in a phase-3, single blind, multicentre, randomized clinical trial.

Optimum formulation of Biological-E's protein subunit CORBEVAX™ vaccine was selected in phase-1 and -2 studies and found to be safe and immunogenic in healthy adult population. This is a phase-3 prospective, single-blinded, randomized, active controlled study conducted at 18 sites across India in 18-80 year-old subjects. This study has two groups; (i) immunogenicity-group, participants randomized either to CORBEVAX™ (n = 319) or COVISHIELD™ arms (n = 320). (ii) Safety-group containing single CORBEVAX™ arm (n = 1500) and randomization is not applicable. Healthy adults without a history of COVID-19 vaccination or SARS-CoV-2 infection were enrolled into immunogenicity arm and subjects seronegative to SARS-CoV-2 infection were enrolled into the safety arm. The safety profile of CORBEVAX™ vaccine was comparable to the comparator vaccine COVISHIELD™. Majority of reported AEs were mild in nature in both arms. The CORBEVAX™ to COVISHIELD™ GMT-ratios at day-42 time-point were 1·15 and 1·56 and the lower limit of the 95% confidence interval for the GMT-ratios was determined as 1·02 and 1·27 against Ancestral and Delta strains of SARS-COV-2 respectively. Both COVISHIELD™ and CORBEVAX™ vaccines showed comparable seroconversion post-vaccination against anti-RBD-IgG response. The subjects in CORBEVAX™ cohort also exhibited higher interferon-gamma secreting PBMC's post-stimulation with SARS-COV-2 RBD-peptides than subjects in COVISHIELD™ cohort.

Safety, tolerability and immunogenicity of Biological E's CORBEVAX™ vaccine in children and adolescents: A prospective, randomised, double-blind, placebo controlled, phase-2/3 study.

BACKGROUND: After establishing safety and immunogenicity of Biological-E's CORBEVAX™ vaccine in adult population (18-80 years) in Phase 1-3 studies, vaccine is further tested in children and adolescents in this study. METHODS: This is a phase-2/3 prospective, randomised, double-blind, placebo-controlled study evaluating safety, reactogenicity, tolerability and immunogenicity of CORBEVAX™ vaccine in children and adolescents of either gender between <18 to ≥12 years of age in Phase-2 and <18 to ≥5 years of age in Phase-Phase-2/Phase-3 with placebo as a control. This study has two age sub-groups; subgroup-1 with subjects <18 to ≥12 years of age and subgroup-2 with subjects <12 to ≥5 years of age. In both sub groups, eligible subjects (SARS-CoV-2 RT-PCR negative and seronegative at baseline) were randomized to receive either CORBEVAX™ vaccine or Placebo in 3:1 ratio. FINDINGS: The safety profile of CORBEVAX™ vaccine in both pediatric cohorts was comparable to the placebo-control group. Majority of reported adverse events (AEs) were mild in nature. No severe or serious-AEs, medically attended AEs (MAAEs) or AEs of special interest (AESI) were reported during the study period and all reported AEs resolved without any sequelae. In both pediatric age groups, CORBEVAX™ vaccinated subjects showed significant improvement in humoral immune-responses in terms of anti-RBD-IgG concentrations, anti-RBD-IgG1 titers, neutralizing-antibody (nAb)-titers against Ancestral-Wuhan and Delta-strains. Significantly high interferon-gamma immune- response (cellular) was elicited by CORBEVAX™ vaccinated subjects with minimal effect on IL-4 cytokine secretion. INTERPRETATIONS: The safety profile of CORBEVAX™ vaccine in <18 to ≥5 years' children and adolescents was found to be safe and tolerable. Significant increase in anti-RBD-IgG and nAb-titers and IFN-gamma immune-responses were observed post-vaccination in both pediatric age sub-groups. The nAb titers observed in both the pediatric age cohorts were non-inferior to the adult cohort (BECT069 study) in terms of ratio of the GMT's of both the cohorts. This study shows that CORBEVAX™ vaccine is highly immunogenic and can be safely administered to pediatric population as young as 5 years old. The study was prospectively registered with clinical trial registry of India- CTRI/2021/10/037066.