How much do you trust the scientific and medical research behind vaccines recommended for adults in the United States?

Background

Vaccines recommended for adults in the United States go through a rigorous, multi-stage process of scientific review. According to the FDA, vaccines undergo extensive evaluation of laboratory and clinical data to ensure safety, efficacy, purity, and potency before they can be approved for public use. After approval, the CDC and FDA continue to monitor vaccines through systems such as the Vaccine Adverse Event Reporting System and the Vaccine Safety Datalink. Despite this infrastructure, public trust in vaccine guidance has become a prominent national debate. A January 2026 KFF tracking poll found that only 47 percent of adults say they have a great deal or fair amount of trust in the CDC to provide reliable information about vaccines, the lowest level since the COVID-19 pandemic began. Recent changes to the federally recommended childhood vaccine schedule, which reduced the number of diseases targeted for routine vaccination from 17 to 11, have intensified scrutiny of federal vaccine policy. A November 2025 Pew Research Center survey found that while 84 percent of Americans still say the benefits of the MMR vaccine outweigh its risks, support for school vaccine requirements dropped from 82 percent in 2019 to 69 percent in 2025.

Those who express high confidence in vaccine research point to decades of clinical evidence and the multi-phase trial process that typically takes years of testing on thousands of participants before a vaccine reaches the public. The World Health Organization has estimated that vaccines have saved more than 150 million lives over the past 50 years. Supporters also note that post-market surveillance systems have successfully identified rare adverse events, such as the link between COVID-19 vaccines and myocarditis, demonstrating that the safety system works as designed. On the other side, critics raise concerns about the speed at which some newer vaccines, particularly COVID-19 vaccines, were developed and authorized under emergency use. CDC data from February 2026 show that the most commonly reported vaccination concern among adults was possible serious or unknown side effects, cited by about 31 percent of respondents regarding COVID-19 vaccines. A 2025 study published in Scientific Reports found that both institutional distrust and susceptibility to misinformation independently predict vaccine skepticism, suggesting the debate is driven by overlapping but distinct factors.

The stakes of this debate are significant and immediate. The United States recorded more than 4,000 measles cases since January 2025, with multiple states falling below the vaccination threshold needed to prevent sustained transmission. Confidence varies sharply by vaccine type: according to KFF, 82 percent of adults express confidence in the safety of polio vaccines, but only 48 percent say the same about COVID-19 vaccines for children. Vaccination uptake among adults also remains uneven, with CDC data showing that as of January 2026, only about 16 percent of adults 18 and older had received the updated COVID-19 vaccine and roughly 44 percent had received a flu vaccine. How Americans weigh the scientific evidence behind adult vaccines will shape not only individual health decisions but also community-level immunity, public health funding, and the future direction of federal vaccination policy.