Only 37% and 22% reported receipt of flu and COVID vaccines, respectively.
The survey of adults in EDs in 8 US cities finds 86% were not up to date with recommended vaccines, but nearly half said they would be willing to get a missing shot if offered.
Experts say the move risks national security by leaving the US vulnerable to the next pandemic virus.
Pregnant women, infants, and people aged 65 years and older are at increased risk for poor flu outcomes.
Vaccination also benefitted unvaccinated people, although not as much as for the vaccinated.
The Influenza Vaccines Research and Development (R&D) Roadmap Initiative has accomplished 14% of its high-priority research goals and made progress on another 83%.
Shipments come on the heels of a severe flu season and record deaths in children.
The drug's prevention efficacy was 76% in the 450-mg group, 61% in the 300-mg group, and 58% in the 150-mg group.
Maternal vaccination reduced the risk of influenza by 51% for infants up to 2 months old.
The company said an mRNA flu vaccine has the potential to more closely match circulating strains.
