COVID-19 and Influenza vaccine co-administration, and missed opportunities to increase COVID-19 vaccination coverage among U.S. adults, 2023-2024

COVID-19 and influenza vaccines are key in protecting against severe clinical outcomes, yet updated COVID-19 vaccination coverage has declined over time and remains much lower than for influenza. Our study aimed to understand the uptake of both COVID-19 and influenza vaccines (including co-administration) and missed opportunities for COVID-19 vaccination during the 2023-2024 respiratory virus season. We surveyed a representative sample of 4022 non-institutionalized U.S. adults and examined COVID-19 and influenza vaccine uptake, and eligibility for and willingness to receive the COVID-19 vaccine. Among all surveyed adults, 19.2% (95% CI 18.0 - 20.5) received both the updated 2023-2024 COVID-19 and influenza vaccines. Co-administration of the influenza vaccine among COVID-19 vaccine recipients was higher (48.5%, 95% CI 45.2 - 51.9) than co-administration of the COVID-19 vaccine among influenza vaccine recipients (22.9%, 95% CI 21.0 - 24.9). Among surveyed adults, 11.2% had received the seasonal influenza vaccine alone and were eligible and willing to receive the COVID-19 vaccine but had not, corresponding to 28.9 million adults who missed an opportunity for COVID-19 vaccination. Given the higher uptake of the influenza vaccine, increasing COVID-19 vaccine co-administration among adults who receive the influenza vaccine could greatly enhance protection against COVID-19 during the respiratory virus season.