Vaccine, Booster and Natural Antibody Binding to SARS-CoV-2 Omicron (BA.1) Spike Protein and Vaccine Efficacy

The SARS-CoV-2 Omicron variant (BA.1) has 25 unique mutations to the Spike glycoprotein, suggesting the efficacy of current vaccines against the new variant may be seriously degraded. A fully quantitative antibody binding study was performed for Spike Omicron (SO) and original Spike (S) proteins simultaneously on three cohorts of patients: convalescent following RT-PCR-confirmed infection in early 2020, double-vaccinated at ≥2 weeks, and vaccine boosters. The average (mode) of the booster cohort response distributions were 15.1 mg/L and 13.4 mg/L for S and SO, respectively, compared with the significantly lower double-vaccinated average, S=2.4 mg/L, SO=2.0 mg/L, and natural infections average S=2.0 mg/L, SO = 1.8 mg/L. A preliminary epitope degradation screen was performed for a panel of antibodies raised to the S1 and S2 regions of the original S protein. The panel showed significant degradation to antibody epitopes in the S1 region. Differential antibody binding of the vaccine response to S and SO suggests vaccine efficacy may be reduced by up to 50% against the Omicron variant. ### Competing Interest Statement Prof Shaw is a Director and Founder of Attomarker Ltd ### Funding Statement Exeter University Alumni, Attomarker Ltd funded PhD studentship at the University of Exeter and Attomarker Ltd direct funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The samples were collected with informed consent. The use of the samples was approved by Biosciences Research Ethics Committee, University of Exeter I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors