ABSTRACT
Background: COVID-19 in paediatric ages could result in hospitalizations and death. In addition, excluding children from vaccination could turn them into reservoirs of the SARS-COV-2. Safe and effective COVID-19 vaccines are urgently needed for large-scale paediatric vaccination. ISMAELILLO study aimed to evaluate safety and immunogenicity of two strengths of a new recombinant receptor-binding domain (RBD) protein vaccine (Abdala) in paediatric population. Methods: A double-blinded, multicentre, randomised, phase 1/2 clinical trial was conducted in nine polyclinics in the province of Camagüey, Cuba. Healthy children and adolescents were stratified according to age (3-11 years old, or 12-18 years old) and they were randomly assigned (1:1; block size four) in two dosage level groups of vaccine to receive three intramuscular doses of 25 µg or 50 µg of RBD, 14 days apart. Main safety endpoint was analyzed as the percentage of serious adverse reactions during vaccination up to 28 days after the third dose (Day 56) in participants who received at least one dose vaccination. The primary immunogenicity endpoint assessed was seroconversion rate of anti-RBD IgG antibody at day 56. The immunogenicity outcomes were assessed in the per-protocol population. This trial is registered with Cuban Public Registry of Clinical Trials, RPCEC00000381. Findings: Between July 15, 2021, and August 16, 2021, 644 paediatric subjects were screened, of whom 592 were enrolled after verifying that they met the selection criteria: firstly 88 were included in Phase 1 of the study and 504 who completed Phase 2. The vaccine was well tolerated. Injection site pain was the most frequently reported local event (143 [8·4%] of 1707 total doses applied), taking place in 66/851 (7·8%) in the 25 µg group and in 77/856 (9·0%) in the 50 µg. The most common systemic adverse event (AE) was headache: 23/851 (2·7%) in the 25 µg group and 19/856 (2·2%) in the 50 µg. Reactogenicity was mild or moderate in severity, represented in 75% of cases by local symptoms, completely resolved in the first 24-48 h. Twenty-eight days after the third dose, seroconversion anti-RBD IgG were observed in 98·2% of the children and adolescents (231/234) for the 50 µg group and 98·7% (224/228) for the 25 µg group without differences between both strength. The specific IgG antibody geometric mean titres (GMT) showed higher titres between participants who received Abdala 50 µg (231·3; 95% CI 222·6-240·4) compared to those who received 25 µg (126·7; 95% CI 121·9-131·7). The mean ACE2 inhibition %, were 59·4% for 25 µg, and for 50 µg, 72·9% (p < 0·01). Both strength elicited neutralising activity against the SARS-CoV-2, specifically (18·3; 95% CI 14·7-22·78) for Abdala 25 µg and (36·4; 95% CI 30·26-43·8) for 50 µg to the selected sample analyzed. Interpretation: Abdala vaccine was safe and well tolerated at both antigenic strength levels tested in participants aged between 3 and 18 years. Regarding immunogenicity, Abdala Vaccine stimulated the production of specific IgG antibodies against the RBD of SARS-CoV-2 as well as the production of ACE2 inhibition titres and neutralising antibodies (Nab) in children and adolescents. Funding: Centre for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba.
ABSTRACT
ObjectivesAn IFN-2b and IFN-{gamma} combination has demonstrated favorable pharmacodynamics for genes underlying antiviral activity which might be involved in the defense of a host from a SARS-CoV-2 infection. Considering this synergy, we conducted a randomized controlled clinical trial for efficacy and safety evaluation of subcutaneous IFN - 2b and IFN-{gamma} administration in patients positive for SARS-CoV-2. MethodsWe enrolled 19-82 years-old inpatients at the Military Central Hospital Luis Diaz Soto, Havana, Cuba. They were hospitalized after confirmed diagnosis for SARS-CoV-2 RNA by real-time reverse transcription polymerase chain reaction. Patients were randomly assigned in a 1:1 ratio to receive either, subcutaneous treatment with a co-lyophilized combination of 3.0 MIU IFN-2b and 0.5 MIU IFN-{gamma} (HeberFERON, CIGB, Havana, Cuba), twice a week for two weeks, or thrice a week intramuscular injection of 3.0 MIU IFN-2b (Heberon(R) Alpha R, CIGB, Havana, Cuba). Additionally, all patients received lopinavir-ritonavir (200/50 mg every 12 h) and chloroquine (250 mg every 12 h, i.e.standard of care). The primary endpoints were, from the start of treatment, the time to elimination of viral RNA and the time to progression to severe COVID-19. The protocol was approved by the Ethics Committee on Clinical Investigation from the Hospital and the Center for the State Control of Medicines, Equipment and Medical Devices in Cuba. Informed consent was obtained from each participant (INSTITUTION PROTOCOL IG/IAG/CV/2001). ResultsA total of 79 patients with laboratory-confirmed SARS-CoV-2 infection, including symptomatic or asymptomatic conditions, fulfilled the inclusion criteria and underwent randomization. Thirty-three subjects were assigned to the HeberFERON group, and 33 to the Heberon Alpha R group. Sixty-three patients were analyzed for viral elimination, of these 78.6% in the HeberFERON group eliminated the virus after 4 days of treatment versus 40.6% of patients in the Heberon Alpha R groups (p=0.004). Time to reach the elimination of SARS-CoV-2, as measured by RT-PCR was 3.0 and 5.0 days for the HeberFERON and Heberon Alpha R groups, respectively. A significant improvement in the reduction of time for virus elimination was attributable to HeberFERON (p=0.0027, Log-rank test) with a Hazard Ratio of 3.2 and 95% CI of 1.529 to 6.948, as compared to the Heberon Alpha R treated group. Worsening of respiratory symptoms was detected in two (6.6%) and one (3.3%) patients in HeberFERON and IFN-2b groups, respectively. However, none of the subjects transited to severe COVID-19 during the study or during the following clinical evaluation (21 more days). RT-PCR on day 14 after the start of the treatment was negative to SARS-CoV-2 in 100% and 91% of patients of the combination of IFNs and IFN-2b, respectively. Elimination in HeberFERON treated patients was related to a significant increase in lymphocytes counts and also a significant reduction in CRP as early as 7 days after commencing the therapeutic schedule. All the patients in both cohorts recovered and had their laboratory parameters return to normal values by day 14 after treatment initiation. Adverse events were identified in 31.5% of patients, 28.5% in the control group, and 34.4% in the HeberFERON group, with the most frequent adverse event being headaches (17.4%). ConclusionsIn a cohort of 63 hospitalized patients between 19 to 82 years-old with positive SARS-CoV-2, HeberFERON significantly eliminated the virus on day 4 of treatment when compared to treatment with IFN-2b alone. However, Heberon Alpha R alone also showed efficacy for the treatment of the viral infection. Both treatments were safe and positively impacted on the resolution of the symptoms. None of the patients developed severe COVID-19.
