ABSTRACT
Intro: With the first case of COVID-19 in Cuba on March 11, 2020, the Center for Genetic Engineering and Biotechnology in Havana began an extensive vaccine program. Two vaccines based on RBD recombinant protein were developed, one for systemic administration "Abdala" and one mucosal vaccine "Mambisa". Abdala received the EUA in July 2021 and "Mambisa" completed its clinical development as a booster dose for convalescent subjects. Method(s): Two doses (25 and 50 microg) and two schedules (0-14-28 and 1-28-56 days) were evaluated in phase I clinical trials with volunteers 19 to 54 years old. The phase II and III clinical trials were also double-blind, randomized, and placebo-controlled, and included respectively 660 and 48,000 volunteers from 19 to 80 years. The anti-RBD titers were evaluated using a quantitative ELISA system developed at the Center for Immunoassay, Havana Cuba, and ELECSYS system from Roche. The RBD to ACE2 plate-based binding competitive ELISA was performed to determine the inhibitory activity of the anti-RBD polyclonal sera on the binding of the hFc-ACE2 coated plates. The neutralization antibody titers were detected by a traditional virus microneutralization assay (MN50). Finding(s): The Abdala vaccine reached 92.28% efficacy. The epidemic was frankly under control in Cuba after the vaccine introduction having reached the highest levels of cases and mortality in July 2021 with the dominance of the Delta strain. The peak of the Omicron wave, unlike other countries, did not reach half of the cases of the Delta wave with a significant reduction in mortality. The mucosal vaccine candidate "Mambisa" completed its clinical development as a booster dose for convalescent subjects reaching the trial end-point. Conclusion(s): Vaccine composition based on RBD recombinant antigen alone is sufficient to achieve high vaccine efficacy comparable to mRNA and live vaccine platforms. The vaccine also protects against different viral variants including Delta and Omicron strains.Copyright © 2023
ABSTRACT
A vaccine is a material administered to an individual to boost their immune system's resistance against infection. Diseases that can be prevented by vaccination can be controlled and eradicated with proper vaccine handling and storage. It is crucial to formulate and deliver stable, effective and safe vaccines. Since vaccines are intricate biological products so any kind of temperature fluctuation can result in reduction of their effectiveness. To prevent this, cold storage facility is set up;refrigerators, thermometers and storage protocols are in place. The main vaccines distributed for COVID in India are Covishield and Covaxin. In order to maintain a cold chain supply for these vaccines, they must be transported and stored at a regulated temperature in accordance with the manufacturer's guidelines. The end-to-end supply chain for COVID-19 vaccines must adhere to specific cold chain standards from manufacturing to distribution in warehouses and healthcare facilities. Audits for cold chains and temperature monitoring should be performed regularly on the vaccine lots to ensure proper distribution practices are adhered. The present study focuses on the good distribution practice and storage of vaccines. Copyright © 2022 Wolters Kluwer Medknow Publications. All rights reserved.
ABSTRACT
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.