People who say they’ll get vaccinated against COVID and flu often don’t. Why not?
Laine BergesonToday at 10:36 a.m.
COVID-19
Influenza, General
Influenza Vaccines
Low vaccination rates are often attributed to vaccine hesitancy, but people who express an unwillingness to get vaccinated aren’t the only ones who sometimes forgo immunizations. Even people who intend to get vaccinated don’t always follow through.
Research published this week in Vaccine found that 39% of participants who said they were willing to receive a COVID-19 vaccine during the 2025-26 respiratory virus season remained unvaccinated by the end of the season. That included 66% of people who said they would probably get the vaccine and 24% who said they would definitely get the vaccine. Among participants who planned to get a flu vaccine, 16% remained unvaccinated by March 2026.
“Research examining vaccine uptake has largely focused on vaccine hesitancy and willingness to vaccinate, often treating stated intentions as proxies for subsequent behavior,” write the researchers, led by a team at the Institute for Implementation Science in Population Health in New York City. “However, intending to be vaccinated does not necessarily translate into subsequent vaccine receipt, and under-vaccination may reflect not only vaccine refusal, but also breakdowns in the pathway from willingness to action.”
Factors tied to missed vaccinations
For the study, the researchers analyzed data from 3,390 US adults who reported their vaccination histories and vaccination plans in August 2025 and whose vaccination status was assessed in March 2026.Participants were considered vaccine-willing if they had been vaccinated against flu or COVID the previous season or if they said they planned to get vaccinated during the 2025-26 season. Overall, 73% said they were willing to receive the flu vaccine, and 68% were willing to receive the COVID vaccine.
Among vaccine-willing participants, the strongest predictor of remaining unvaccinated was not having been vaccinated during the previous respiratory virus season. Compared with those who had been vaccinated during the 2024–25 season, participants who hadn’t been vaccinated the previous season were roughly four times as likely not to get the flu vaccine (adjusted risk ratio [aRR], 4.04) and about three times as likely not to get the COVID vaccine (aRR, 3.01) in 2025–26.
Participants experiencing food or housing insecurity were twice as likely to remain unvaccinated against the flu (aRR, 1.99) during the 2025–26 season and 1.5 times more likely to remain unvaccinated against COVID (aRR, 1.47).
Barriers to accessing healthcare also played a role, with those who reported barriers being nearly two times more likely to forgo the flu vaccine (aRR, 1.89) and 1.5 times more likely to forgo a COVID vaccine (aRR, 1.51).
Vaccine-willing participants who were not confident in vaccine safety were nearly three times as likely to skip the flu vaccine (aRR, 2.95) and more than twice as likely to skip the COVID vaccine (aRR, 2.21) as those who were very confident.
Inconvenience a barrier for vaccine-willing adults
Among vaccine-willing participants who didn’t get the flu shot, the most commonly reported barrier was difficulty finding a convenient time, place, or appointment (33% vs 7.5% of non-willing non-vaccinators), while non-willing non-vaccinators were most likely to report concerns about side effects as their reason for skipping the flu shot (29.8% vs 10.1% among vaccine-willing participants).Non-willing participants who didn’t receive the flu vaccine also reported believing they could stay healthy in other ways (25.8% vs 8.3%) and lacking trust in vaccine safety (22.6% vs 4.7%) as reasons for avoiding the flu vaccine.
An inability to find a convenient time, place, or appointment was also the most frequently cited barrier for vaccine-willing participants who did not get vaccinated against COVID (24.2% vs 4.7% of vaccine-unwilling participants).
Roughly 17% of vaccine-willing participants who didn’t get vaccinated said their healthcare provider hadn’t recommended the COVID vaccine (16.7% vs 9.9%). About 8% cited insurance or cost barriers (8.1% vs 1.8%), and around 7% (7.4% vs 1.6%) said they did not know where to get the vaccine.
Vaccine-unwilling participants who didn’t get vaccinated against COVID more commonly reported concerns about side effects (40.9% vs 11.3% among vaccine-willing participants), lack of trust in vaccine safety (33.8% vs 4.3%), and believing they could stay healthy in other ways (19.6% vs 6.7%).
The findings line up with previous research on barriers to vaccination and may help public health experts address gaps in vaccine uptake.
“Reported reasons for non-vaccination among vaccine-willing participants suggest that many of these gaps reflected addressable barriers to follow-through, including difficulty finding a convenient time, place, or appointment and, for COVID-19, lack of healthcare provider recommendation,” write the researchers.
“These findings align with prior work showing that health insurance coverage, provider recommendations, and convenience are important determinants of adult vaccination uptake.”