Comparing the antibody repertoire of XBB1.5 booster immunization with mRNA or protein-based platforms

---

Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B545
Abstract ID: 5675

Presenting Author:
Igor Lobo , Postdoctoral Researcher at Icahn Sch. of Med., Mount Sinai

Abstract:

The SARS-CoV-2 spike (S) protein is an essential target for neutralizing antibodies, accumulating mutations, and generating variants of concern (VOC). The Omicron variant is a VOC that continues to evolve into antibody-resistant subvariants, such as XBB1.5. This led to the approval of an updated mRNA vaccine and a protein-based vaccine to target the XBB1.5 strain. However, whether these vaccines can elicit functional monoclonal antibodies specifically against this strain and how the different vaccine platforms (mRNA vs protein) shape the antibody repertoire is unknown. Here, we analyzed the antibody repertoire of five humans who either received the updated mRNA or the protein-based vaccine. We used the Immcantation framework to analyze the VDJ sequences. We assigned V, D, and J genes using IgBlast according to the Change-O pipeline. Clonal groups were defined using the SCOPer package v.1.3.0, and then we calculated somatic hypermutation (SHM) for the BCR sequences. Firstly, we reconstructed germline V and J sequences. The total number of mutations was found for the V gene using SHazaM v.1.2.0, and clonal lineage trees were built using the dowser package v.2.0. We are currently expressing human monoclonal antibodies from the participants and will assess binding, neutralization, and affinity. Our results will compare the antibody activity elicited by vaccination between protein-based (Novavax) and mRNA (Pfizer/Moderna) in humans receiving the XBB1.5 booster.