Concurrent administration of COVID-19 and influenza vaccines enhances Spike-specific antibody responses
https://www.biorxiv.org/content/10.1101/2023.09.12.557347v1

IgG1 responses to SARS-CoV-2 Spike were higher at peak immunogenicity and 6 months following concurrent administration compared with separate administration of the COVID-19 and influenza vaccines.