Route-Dependent Effects of Pre-Existing Anti-Ad5 Immunity on Systemic, Mucosal and Lymph Node B Cell Responses to an Ad5-Vectored Vaccine

Background/Objectives: Pre-existing anti-Ad5 immunity (PEI) impairs the immunogenicity of intramuscular (IM) Ad5-vectored vaccines. Whether respiratory immunization can better preserve vaccine-induced immunity remains unclear.

Methods

We established a murine PEI model to compare immune responses following IM, intranasal (IN), or intratracheal (IT) vaccination with an Ad5-vectored SARS-CoV-2 vaccine.