A live attenuated vaccine confers superior mucosal and systemic immunity to SARS-CoV-2 variants

We describe the cellular response to SARS-CoV-2 infections in Syrian hamsters previously immunized with mRNA, Adenovirus, and life-attenuated virus vaccines. Two experiments were conducted. In the first, single vaccination were done with either an mRNA vaccine, and adenovirus vector vaccine, or the life-attenuated sCPD9 (prime only). The second experiment follows prime-boost strategies with the combination adenovirus + adenovirus, mRNA + mRNA, sCPD9 + sCPD9, and mRNA + sCPD). In both experiments, there were also mock-vaccinated animals. Histopathology was performed from lungs and nasal mucosa, antibody levels were determined in blood and nasal washes, bulk RNA sequencing was performed from lungs, and scRNA-seq was performed from lung, blood and nasal mucosa. Note that the data quality of the blood samples from experiment 1 is very poor.