Concurrent administration of COVID-19 and influenza vaccines enhances Spike-specific antibody responses.

The bivalent COVID-19 mRNA boosters became available in fall 2022 and were recommended alongside the seasonal influenza vaccine. However, the immunogenicity of concurrent versus separate administration of these vaccines remains unclear. Here, we analyzed antibody responses in healthcare workers who received the bivalent COVID-19 booster and the influenza vaccine on the same day or different days. 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. These data suggest that concurrent administration of these vaccines may yield higher and more durable SARS-CoV-2 antibody responses.
Competing Interests: POTENTIAL CONFLICTS OF INTEREST R.P.M. receives financial support from AbbVie, Pfizer, GSK, the Bill and Melinda Gates Foundation, the Wellcome Trust, the United States Department of Defense, and the National Institute of Health. The remaining authors declare no competing interests.