Safety and Immunogenicity of Omicron Variant-Matched Vaccine Booster in Adults — SH-MO-214  

COVID-19 Clinical Trial

Official title: Phase 2, Randomized, Observer-Blind, Investigator-Initiated, Collaborative Study to Evaluate the Safety and Immunogenicity of Omicron Variant-Matched Vaccine Booster in Adults

Status Recruiting

Clinical Trial Summary

The five recently emerged SARS-CoV2 variants that were designated as VOCs are the Alpha variant, Beta variant, Gamma variant, Delta variant and the Omicron variant. The current dominant Omicron variant was designated a VOC by WHO on Nov 26, 2021, and was found to comprise 85% of reported variants in late January 2022. Studies have shown that the prevalent Omicron mutations in the S1 subunit RBD region and NTD region could dramatically change the antigenic features of the viral spike, leading to significantly reduced neutralization Omicron harbors 30 signature mutations (>50% prevalence) of which 15 are in the S1 subunit RBD region and 8 are in the S1 subunit NTD region. Omicron is a highly contagious variant with threatening immune evasion capabilities even despite robust immune response. Initial modeling showed the Omicron variant being 2.8 times more infectious than the Delta variant. While current vaccines are losing protection against Omicron with respect to infection and mild disease, there is still considerable protection from hospitalisation and severe COVID-19, especially after a booster dose. The International Coalition of Medicines Regulatory Authorities (ICMRA) COVID-19 Omicron Variant Workshop encouraged the international scientific community and vaccine developers to look at alternative approaches to monovalent vaccines. In ICMRA's view, companies should also explore the feasibility of developing bivalent or multivalent variant vaccines to determine if they offer advantages to monovalent vaccines. As advised by ICMRA, the investigated vaccine, mRNA-1273.214 is a bivalent vaccine containing the ancestral SARS-CoV-2 and the Omicron variant spike sequences that will be evaluated as a heterologous boost.

Clinical Trial Description

The trial aims to evaluate the safety and immunogenicity of the investigated covalent vaccine, mRNA-1273.214, administered as a heterologous vaccine after the primary series vaccination and boost with the BNT162b2 or mRNA-1273, in healthy adults aged ≥21 years. Three different treatment arms will be compared with participants being administered either: 1. mRNA-1273.214 (Day 1) and mRNA-1273.214 (Day 56) 2. mRNA-1273.214 (Day 1) and placebo (Day 56) 3. mRNA-1273 (Day 1) and placebo (Day 56) Study procedures include two administrations of vaccine and/or placebo, nasopharyngeal swab for SARS-CoV-2 PCR, blood draws for antibody response: IgG, IgA, pseudo-neutralization antibody (ab) titers, B-Cell response, T-Cell response, and solicited and non-solicited adverse events. Subjects will be asked to complete an electronic diary for 7 consecutive days after each vaccination dose, regarding vaccine-related symptoms + temperature measured at home. One week after the day of vaccination or placebo, subjects will be asked to complete a COVID-19 questionnaire once a week, in which they will have to answer the question of whether they have experienced COVID-19 symptoms. Adverse reactions will be measured by the occurrence of solicited injection site reaction and systemic reaction from the time of each vaccination through 7 days post each vaccination/placebo administration. Unsolicited non-serious Adverse Events (AEs), Serious adverse events (SAEs), new-onset chronic medical conditions (NOCMCs), and medically-attended adverse events (MAAEs) will be collected from baseline through 6 months after the first booster dose vaccination. Nasopharyngeal Swab for SARS-CoV-2 PCR, Blood Samples For Immunogenicity Assessment, Serology and PBMC will be collected at each study visit (6 times during the subject's participation in the study). ;

Related Conditions & MeSH terms

• COVID-19
• COVID-19 Pandemic
• Immunogenicity

• NCT number: NCT05383560
• Study type: Interventional
• Source: Sheba Medical Center
• Contact: Gili Regev-Yochay, MD
• Phone: +97235308520
• Email: Gili.Regev@sheba.health.gov.il
• Status: Recruiting
• Phase: Phase 2
• Start date: September 5, 2022
• Completion date: July 2023