Is the US Headed for an Infectious Disease Pandemic?

The next 25 years could see an increase in millions of preventable infections resulting in thousands of deaths in the US if childhood vaccination rates continue to decline, projections from a recent study revealed.¹ Measles is projected to become endemic again within 21 years at current vaccine levels. With further decline, rubella and polio could also return.

On May 8, the US surpassed 1000 confirmed measles cases across 31 states/jurisdictions.² Most cases (96%) were among unvaccinated individuals or those with unknown vaccination status, with 93% linked to 12 outbreaks. The age group most affected is 5 to 19 years (38%). Hospitalizations occurred in 13% of cases, with the highest rate (23%) in children under 5 years. There have been 3 confirmed measles-related deaths.

The decline in vaccination rates has resulted in localized gaps in herd immunity and contributed to a resurgence of measles cases observed in early 2025.¹ Current models project that if vaccination levels remain unchanged, there could be a staggering 851,300 cases of measles, alongside 190 cases of rubella, 18 cases of polio, and 8 cases of diphtheria. Over the next 25 years, this situation could unfortunately lead to 2550 deaths and approximately 170,200 hospitalizations.

Although the vaccination rate has been declining for years, a number of states have seen at least a 10% drop in vaccinations just from 2023 to 2024. In 2025, the Trump administration ushered in leaders who appear to sympathize more closely with Americans who chose to withhold vaccinations from their children than previous administrations, with stances favoring a reduction in vaccination guidance.³ HHS Secretary Robert F. Kennedy Jr; FDA Commissioner Marty Makary, MD, MPH; and Vinay Prasad, MD, MPH, as the FDA’s Center for Biologics Evaluation and Research (CBER) new director, have all made claims that confidence in the health institutions is at an all-time low among the American public; Makary has described it as an “epidemic of distrust.”

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Upon the announcement of Prasad’s arrival, the XBI biotech exchange-traded fund fell more than 6% on the day of the announcement, with gene and cell therapy companies hit particularly hard—some stocks plunging as much as 30%. Concerns stem largely from Prasad’s outspoken criticism of high-profile FDA decisions.fund fell more than 6% on the day of the announcement, with gene and cell therapy companies hit particularly hard—some stocks plunging as much as 30%. Concerns stem largely from Prasad’s outspoken criticism of high-profile FDA decisions.

In 2022, Prasad and Markary authored an essay in Journal of Medical Ethics, which argued that among young adults (aged < 30), the harm reduction provided to the individual—and to those the individual could potentially transmit the virus to—by the COVID-19 boosters failed to ethically justify the mandates enacted on some college campuses.⁴

Under Prasad's leadership, industry leaders fear heightened regulatory scrutiny and stricter approval processes. Shortly before the announcement, Kennedy established a new policy requiring all new vaccines to undergo placebo-controlled trials before approval, a move that health care leaders anticipate will delay the development of vaccines and even further inhibit the public’s confidence. Even more have expressed concerns about the ethics and harms of administering placebos when there are vaccines that have been tested and proven to be effective.^3,5

Rigorous research and safety testing should always be the priority of developers and regulatory agencies. However, delaying processes further, at a time when previously contained disease rates are rapidly rising and vaccination rates proceed in the opposite direction, can lead to mounting pressure.

As immunization research progresses, there is an urgent need for a new tuberculosis (TB) vaccine to prevent a projected increase in cases by 2035.⁶ Currently, the only available vaccine is for infants and young children. According to the World Health Organization (WHO), a TB vaccine that targets all age groups could significantly reduce global TB mortality and incidence by up to 95%. To achieve this goal, the WHO has established specific criteria for a new TB vaccine that addresses the limitations of the current Bacille Calmette-Guerin vaccine.

In recent times, vaccine hesitancy increased around the 2019 measles resurgence, prompting the WHO to name it a top global health threat. The COVID-19 pandemic further amplified antivaccine sentiment, with social media becoming a central hub for misinformation. A 2021 study showed that exposure to such misinformation significantly reduced vaccine intent, even among initially willing individuals.

Changes to the vaccine schedule or the continued influence of vaccine skepticism could accelerate these trends, the authors of the previously mentioned study warned.¹ “Recently, more abrupt changes to the childhood vaccine schedule have been debated, including removal of certain vaccines entirely,” they wrote. “Even though a high level of population immunity remains due to decades of vaccination and, historically, infection-acquired immunity, declines in routine vaccinations will increase the number of susceptible persons over time and may lead to [a] resurgence of many infectious diseases.”

References

1. Jeremias S. Falling vaccine coverage threatens a surge in preventable diseases. AJMC^®. April 24, 2025. Accessed May 12, 2025. https://www.ajmc.com/view/falling-vaccine-coverage-threatens-a-surge-in-preventable-diseases

2. Measles cases and outbreaks. CDC. May 2, 2025. Accessed May 8, 2025. https://www.cdc.gov/measles/data-research/index.html

3. Grossi G. Biotech stocks slide after FDA selects Prasad to lead CBER. AJMC. May 7, 2025. Accessed May 12, 2025. https://www.ajmc.com/view/biotech-stocks-slide-after-fda-selects-prasad-to-lead-cber

4. Bardosh K, Krug A, Jamrozik E, et al. COVID-19 vaccine boosters for young adults: a risk benefit assessment and ethical analysis of mandate policies at universities. J Med Ethics. 2024;50(2):126-138. doi:10.1136/jme-2022-108449

5. Southwick R. Kennedy pushes placebo testing for new vaccines, frustrating health leaders. Chief Healthcare Executive^®. May 2, 2025. Accessed May 13, 2025. https://www.chiefhealthcareexecutive.com/view/kennedy-pushes-placebo-testing-for-new-vaccines-frustrating-health-leaders

6. Santoro C. Vaccine hesitancy fuels global health crisis amidst multidisease outbreaks. AJMC. August 8, 2024. Accessed May 12, 2025. https://www.ajmc.com/view/vaccine-hesitancy-fuels-global-health-crisis-amidst-multi-disease-outbreaks