Over the past five years, the U.S. has progressively recommended annual coronavirus disease 2019 (COVID-19) boosters for the entire population. Each fall, updated COVID-19 booster doses are released along with seasonal flu vaccines, which are broadly recommended for nearly all individuals aged six months and older. This universal approach contrasts with the strategies of many high-income countries, especially in Europe, where booster and flu shots are generally targeted toward older adults or high-risk populations. In the U.S, vaccination policy follows a one-size-fits-all model, despite calls from researchers for more personalized, risk-based recommendations. Experts argue that it is unreasonable to assume the public cannot understand nuanced, individualized health guidance.
The rapid development and deployment of multiple COVID-19 vaccines in 2020 marked a major public health achievement. However, the benefit of repeated booster doses, especially for low-risk adults who have already been vaccinated or previously infected, remains uncertain. Many Americans, including healthcare professionals, continue to question the need for further boosters.
In the last two years, annual COVID-19 booster uptake has remained low. CDC data shows that fewer than 25% of Americans receive the annual COVID-19 booster. In the 2024-2025 season, uptake was especially limited, with less than 10% of children under 12 years and less than 50% of adults over 75 years. Among healthcare workers, fewer than one-third received the 2023–2024 fall booster.
The low uptake might be contributing to a broader decline in public confidence in vaccines, including long-established vaccines such as the measles-mumps-rubella (MMR) vaccine that has a strong safety and efficacy record. The recent drop in MMR coverage is especially concerning, as it increases the risk of preventable outbreaks and measles-related deaths. In response, the FDA is working to improve public guidance and support further research aimed at rebuilding trust and inform potential strategies for future vaccinations.
The FDA has requested stronger clinical trial data to assess COVID-19 vaccine benefits in healthy people aged 6 months to 64 years without known risk factors for severe disease. These trials must evaluate whether the booster doses significantly reduce symptomatic infection and reduce serious outcomes such as hospitalizations and death. The FDA has emphasized the inclusion of adults aged 50–64 in these studies, amid ongoing international debate over whether individuals in this age group benefit from annual boosters.
FDA guidance specifies that new studies must show a meaningful reduction in the illness, with results that are at least 30% more consistent than chance. These studies will be conducted under “real-world” conditions, including subjects who have had a recent COVID-19 infection (within the past year). Participants will be monitored for approximately 6 months to assess the durability of immune protection. The studies will also include saline placebo controls to identify any injection-related adverse effects.
Importantly, the FDA now acknowledges the need to distinguish between COVID-19 and influenza vaccination strategies. For COVID-19, the agency has embraced a more rational, data-driven approach: maintaining access to vaccines for high-risk groups while requiring rigorous clinical evidence to justify recommendations for low-risk populations. This provides a bridge for everyone to have continued access to the vaccines for any high-risk populations, while also advancing the scientific understanding of vaccine effectiveness through high-quality evidence. These trials are expected to provide the clarity and confidence that both the healthcare system and the public have been seeking.
Reference: Prasad V, Makary MA. An evidence-based approach to Covid-19 vaccination. N Engl J Med. 2025. doi:10.1056/NEJMsb2506929
