Co-administration of DTaP and mRNA COVID-19 vaccines results in altered immune profile and enhanced protection against aerosol challenge of B. pertussis in mice 3042

Abstract Description Children routinely receive COVID-19 mRNA vaccines alongside other regularly scheduled immunizations. It is known that mRNA vaccines are pro-inflammatory in nature which lead to protective immunity. Our goal was to investigate the effects of co-administering the COVID-19 mRNA vaccine alongside the acellular B. pertussis vaccine (DTaP). In this study, mice were immunized with DTaP with or without co-administration of mRNA COVID-19 vaccine. To understand the impact of co-administration, correlates of protection were measured including: early cytokine responses to vaccination, antibody responses to DTaP antigens, and protection against B. pertussis aerosol challenge. DTaP and DTaP-mRNA-bivalent responses were compared to mice immunized with whole cell pertussis vaccine (DTP) since it is known to induce robust protection and long-term immune responses. Furthermore, four decreasing doses of each vaccine was used to simulate waning immunity. Overall, compared to mice immunized with DTaP, co-administration of DTaP+mRNA-bivalent vaccines elicited higher pro-inflammatory cytokine responses, higher antibody responses, and mice were afforded more protection against aerosol challenge of B. pertussis. Current ongoing experiments are focused on T and B cell responses, as well as characterizing single cell transcriptomics of the lymph node at one day post-boost to understand how co-administration of mRNA alongside protein-based vaccines shapes immunity. Funding Sources WVU vaccine development center FHD NIH grant (1R01AI153250-01A1) 10x Genomics: The WVU Flow Cytometry &Single Cell Core Facility is supported by the Institutional Development Awards (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant numbers P30GM121322 (TMECoBRE) and P20GM103434 (INBRE). Topic Categories Vaccines and Immunotherapy (VAC)