CDC Under Strain: What the Evidence Shows — and What Congress Should Examine

The Centers for Disease Control and Prevention (CDC) is a central component of the United States’ Public Health infrastructure. Its responsibilities include disease surveillance, outbreak investigation, laboratory science, vaccination guidance, injury and chronic-disease prevention, environmental-health protection, and preparedness for emerging threats. The agency has historically served as a foundational pillar and is considered the premier of global public health since its founding on July 1, 1946, providing verified critical data, scientific guidelines, and outbreak response support worldwide. Although it remains a major global entity, the agency’s role and public perception have faced evolving challenges and scrutiny in recent years. A new poll indicated that Americans’ trust in the CDC has plummeted since 2025.

Since the beginning of the Trump administration in 2025, the CDC has undergone unusually extensive changes in leadership, staffing, organizational structure, vaccine policy, data publication, and public communications. Some of these changes were explicitly intended by the administration to reduce bureaucracy, alter federal health priorities, and restore what Secretary of Health and Human Services Robert F. Kennedy Jr. described as public trust. Others have been challenged by former CDC leaders, Public Health organizations, employees, researchers, and members of Congress who argue that the changes have weakened scientific independence and operational capacity.

The available evidence does not establish that the CDC has ceased functioning, nor does it support the assertion that every major scientific or surveillance function has been dismantled. CDC continues to investigate outbreaks, publish epidemiological data, operate major surveillance systems, issue vaccination guidance, and maintain its principal centers for infectious disease, environmental health, chronic disease, injury prevention, and One Health.

Nevertheless, there is substantial evidence of institutional disruption. The combination of large workforce reductions, loss of experienced personnel, rapid changes in senior leadership, restructuring of advisory bodies, interruptions in some surveillance-data updates, and changes in the procedures used to establish certain vaccine policies warrants careful congressional oversight and public examination. 

The central question is therefore not whether the CDC has literally ceased to exist. It has not. The more consequential question is whether the United States has weakened some of the institutional capacity, continuity, transparency, and scientific independence on which effective public health decision-making depends.

Workforce reductions and institutional disruption

The administration announced a major restructuring of the Department of Health and Human Services in March 2025, including approximately 2,400 planned reductions at CDC. The reductions were part of a broader effort to reduce the HHS workforce from approximately 82,000 to 62,000 employees. 

The effects were not limited to administrative personnel. The reductions also affected specialists in areas including tobacco control, injury prevention, workplace safety, reproductive health, infectious-disease preparedness, environmental health, and other public-health functions. Approximately 450 CDC employees were subsequently reinstated in June 2025, illustrating both the scale of the initial disruption and the administration’s willingness to revise some personnel decisions. 

Later reductions continued. By the end of 2025, reporting based on CDC workforce information indicated that approximately one-quarter of the agency’s workforce had been lost through layoffs, departures, and related reductions. By early 2026, more than 3,000 public-health workers were reported to have left the agency.

These figures should not be confused with the original claim that 27% of the entire workforce and 80% of senior leadership were simultaneously eliminated. The available evidence does not substantiate those precise figures. 

The significance of workforce reductions is not simply numerical. Public health agencies depend on institutional memory, specialized epidemiological knowledge, laboratory expertise, relationships with state and local health departments, and the ability to mobilize experienced personnel rapidly during an emergency. Losing personnel with that experience can reduce capacity even when an organizational chart continues to show that a program formally exists. 

Leadership instability

The CDC experienced extraordinary leadership turnover. 

Susan Monarez became CDC director in July 2025 after SenaSusan Monarez te confirmation. Less than a month later, she was removed from the position. Her attorneys said that Secretary Kennedy sought her agreement to dismiss senior officials and accept changes to vaccine policy that she considered unsupported by scientific evidence. Administration officials disputed aspects of that account and characterized the dispute in terms of policy alignment and management. 

Four senior CDC officials subsequently resigned, including senior scientific and immunization leaders. They publicly expressed concerns about political interference and the direction of federal vaccine policy. 

Jim O’Neill then became acting CDC director. In February 2026, NIH Director Jay Bhattacharya temporarily assumed the CDC’s leadership while continuing to head NIH. That interim period ended in August 2026, when the Senate confirmed Erica Schwartz as CDC director by a vote of 51–44. CDC currently lists Schwartz as its director. The succession itself is not proof of misconduct. Leadership changes are a normal consequence of a change in presidential administration. The unusually short tenure of one Senate-confirmed director, multiple subsequent acting directors, and the accompanying resignations of senior career officials, however, constitute a significant episode of institutional instability that merits examination. 

The advisory committee on immunization practices

One of the clearest documented changes concerned the Advisory Committee on Immunization Practices (ACIP). In June 2025, Secretary Kennedy removed all 17 sitting voting members of ACIP and replaced them initially with eight new members. HHS said the purpose was to restore public confidence in vaccine policy and address alleged conflicts of interest. Critics argued that replacing the entire committee simultaneously departed from the committee’s traditional continuity and created an unacceptable risk of political influence.

It is important, however, not to characterize every subsequent appointee as lacking scientific qualifications. The current roster includes physicians, pediatricians, an epidemiologist, a neuroscientist, a surgeon, and an MIT professor specializing in healthcare analytics, among others.

The legitimate institutional question is therefore narrower and more consequential: whether advisory committees that formulate recommendations affecting millions of Americans retain sufficient independence, methodological rigor, subject-matter expertise, transparency, and continuity to command public confidence regardless of which political party controls the executive branch.

Changes in COVID-19 vaccination policy

In May 2025, HHS announced that COVID-19 vaccines were being removed from the CDC-recommended schedule for healthy children and pregnant women, with the administration describing the policy as a shift toward individualized decision-making. 

The process differed from the traditional pattern in which ACIP develops recommendations that are subsequently adopted by CDC leadership. That procedural change became a major point of contention. 

The policy has subsequently evolved. CDC’s 2025–26 guidance used shared clinical decision-making for people six months and older, with greater emphasis on individual risk for severe disease. Consequently, it would be inaccurate to state simply that the administration “ended COVID vaccination for children and pregnant women.” The more precise statement is that it removed the previous universal recommendation and replaced it with a substantially narrower policy framework. 

The decision to terminate 22 mRNA vaccine-development investments

In August 2025, HHS announced that Biomedical Advanced Research and Development Authority (BARDA) would terminate or de-scope 22 mRNA vaccine-development investments totaling nearly $500 million. The projects included work involving COVID-19, influenza, and an mRNA-based H5N1 vaccine. 

HHS justified the decision by arguing that available evidence did not demonstrate adequate protection against upper-respiratory infections and that federal resources should instead be directed toward alternative vaccine platforms. 

That explanation should be distinguished from the broader scientific question of whether mRNA vaccines are effective or safe. Independent scientific reviews have disputed the assertion that mRNA vaccines generally “fail to protect effectively” against COVID-19 and influenza. 

The policy question is therefore not whether every mRNA project should automatically have been funded. It is whether terminating an entire class of federal pandemic-preparedness investments was supported by a sufficiently transparent evaluation of the evidence, alternatives, opportunity costs, and national-security implications. 

Public health surveillance and data interruptions

A particularly important finding comes from a study published in Annals of Internal Medicine. Researchers examined more than 1,300 CDC public data records and identified 82 that had previously been updated at least monthly. As of late October 2025, 38 of those 82 — approximately 46% — had experienced unexplained pauses in updating. Thirty-four of the 38 had gone more than six months without an update. Approximately 87% of the paused databases concerned vaccination. The remaining paused systems included respiratory-disease and overdose surveillance. This finding deserves attention, but it must be described precisely.

It does not mean that 46% of all CDC databases were shut down. It refers to 38 of 82 frequently updated public databases selected for the study. Nor does it demonstrate that every interruption was politically ordered. HHS stated that changes to individual dashboards and update schedules could reflect routine data-quality or system-management decisions.

The concern is nevertheless substantial: when public health surveillance data stop being updated without a clear explanation, researchers, physicians, veterinarians, state health departments, journalists, and the public cannot readily distinguish a genuine change in disease patterns from a gap in federal reporting. Transparency about which datasets are delayed, why they are delayed, and when regular reporting will resume is therefore an important institutional safeguard.

The CDC Freedom of Information Act (FOIA) office

Federal court records document that all 23 employees in the CDC FOIA office were placed on administrative leave on April 1, 2025, and that the office ceased operating independently. CDC’s FOIA workload was subsequently transferred into the HHS Office of the Secretary’s FOIA operation.

Thus, saying that the administration “eliminated the CDC’s FOIA processing teams” is substantially supported. It is not accurate, however, to say that this “cut off the legal pathways” for obtaining CDC records. FOIA remains federal law, and HHS currently identifies CDC among the components whose requests are handled through the HHS Office of the Secretary.

The more defensible concern is that eliminating CDC’s specialized FOIA staff and moving the workload into a centralized system could affect processing capacity, institutional knowledge, timeliness, and public access to records.

Those effects are appropriate subjects for congressional oversight because transparency is particularly important when an agency is undergoing major organizational change.

What happened to the CDC’s public health programs?

As of 2026, CDC still maintains:

• the National Center for Chronic Disease Prevention and Health Promotion;
• the National Center for Environmental Health;
• the National Center for Injury Prevention and Control;
• the National Center for Emerging and Zoonotic Infectious Diseases;
• the National Center for Immunization and Respiratory Diseases;
• the National Center for HIV, Viral Hepatitis, STD, and TB Prevention;
• the National Center for Health Statistics; and
• the National Institute for Occupational Safety and Health.

The continued existence of these centers does not mean that their previous staffing, budgets, leadership structures, or capabilities remain unchanged. For example, CDC’s current environmental-health center, the National Center for Environmental Health (NCEH), continues to describe environmental surveillance, laboratory research, environmental-threat detection, and emergency response as core responsibilities. CDC’s Chronic Disease Prevention and Health Promotion continues to operate with a FY2026 budget exceeding $1.4 billion, while the Injury Prevention and Control continues to oversee programs involving overdose, suicide, violence, and other injuries.

The more accurate concern is therefore not that the entire “environmental” or “preventive” component of One Health has disappeared. Rather, workforce reductions and restructuring may have reduced capacity in particular programs, and the magnitude and consequences of those reductions deserve transparent measurement. 

One Health: an important area that remains operational

The CDC’s One Health Office has not been eliminated. CDC continues to describe the office as its lead for One Health activities in the United States and internationally. The office works at the intersection of human, animal, and environmental health, particularly in relation to zoonotic and emerging infectious diseases, pandemic preparedness, environmental threats, and information sharing. 

The United States also released its first National One Health Framework in January 2025. CDC, USDA, and the Department of the Interior developed the framework pursuant to direction from Congress in the 2023 Consolidated Appropriations Act. 

CDC’s current One Health material continues to describe coordination with USDA and the Department of the Interior, and CDC continues to maintain One Health surveillance and response activities.

The One Health Office should therefore not be presented as a program already dismantled. Its importance is better understood as a reason to monitor whether broader workforce and organizational changes reduce the agency’s ability to connect human, veterinary, wildlife, and environmental surveillance. That concern is not theoretical. Diseases can cross boundaries among people, livestock, wildlife, food systems, and the environment. Effective surveillance depends on communication among institutions that traditionally operate in separate sectors. 

Foodborne disease surveillance and the Cyclospora example

Beginning with data collected after July 1, 2025, reporting for most FoodNet pathogens became optional, although Salmonella and Shiga-toxin-producing E. coli remained mandatory within the FoodNet system. CDC states that the change was intended to allow staff to prioritize core activities and notes that other surveillance systems continue to operate. 

It is therefore inaccurate to say that federal foodborne-disease surveillance was simply “disabled.” Indeed, CDC continues to operate PulseNet, a national laboratory network using whole-genome sequencing to identify and investigate foodborne outbreaks. CDC used PulseNet during a 2026 multistate Listeria outbreak. (4,7)

The 2026 Cyclospora outbreak illustrates both the value of surveillance and the danger of drawing conclusions that the evidence does not establish. The outbreak was substantial. CDC identified a multistate outbreak associated with iceberg lettuce and reported 1,644 cases linked to Taco Bell locations by July 17, 2026. By August 24, CDC had received reports of 17,180 laboratory-confirmed domestically acquired cases of cyclosporiasis during the 2026 season. (4,7)

But the evidence presently available does not demonstrate that a federal surveillance shutdown caused the outbreak or prevented its detection. CDC continued to collect case reports and investigate the outbreak through epidemiological, laboratory, and traceback methods. 

The defensible lesson is different: robust surveillance systems are valuable precisely because outbreaks are unpredictable, and reducing surveillance capacity creates risks that may not become visible until a crisis occurs. 

Measles demonstrates why surveillance and vaccination policy matter

The United States has experienced a substantial resurgence of measles. CDC reported 3,294 confirmed measles cases in the United States through September 10, 2026. CDC also reported that U.S. kindergarten MMR vaccination coverage had declined from 95.2% in the 2019–20 school year to 92.4% in 2025–26, leaving an estimated 280,000 kindergartners at increased risk.

These facts establish a significant public health problem. They do not, by themselves, establish that particular changes in federal messaging caused the increase. That distinction matters. Public health policy should be evaluated using evidence capable of separating causation from correlation. At the same time, the measles experience demonstrates why timely vaccination data, disease surveillance, laboratory capacity, and credible public communication are complementary rather than interchangeable functions.

What the evidence does — and does not — establish

The evidence supports several propositions:

• The CDC experienced unusually large workforce reductions beginning in 2025.
• Hundreds of employees were subsequently reinstated, demonstrating that some initial cuts were reversed.
• Senior CDC leadership experienced significant turnover.
• Four senior CDC officials resigned following Susan Monarez’s removal.
• All 17 sitting ACIP members were removed in June 2025 and replaced.
• HHS terminated or de-scoped 22 BARDA mRNA vaccine-development investments.
• The independent CDC FOIA office was shut down and its workload transferred to HHS.
• A peer-reviewed study found unexplained pauses in 38 of 82 frequently updated CDC public-health databases examined.
• CDC continues to operate major surveillance systems and public-health centers.
• CDC’s One Health Office remains operational.
• The United States continues to have functioning federal disease-surveillance and outbreak-response capabilities.
• Significant questions remain about the effect of personnel losses, policy changes, leadership turnover, and data interruptions on the agency’s long-term capacity.

The institutional issue for Congress and the public

The most consequential question is not whether every decision made by the current administration is correct or incorrect. It is whether the United States retains a sufficiently capable, transparent, scientifically rigorous, and professionally independent public-health system to detect threats before they become crises.

A durable public health institution should be able to survive changes in presidential administrations. Republican and Democratic administrations will inevitably establish different priorities. That is inherent in representative government. But surveillance methodology, statistical integrity, laboratory standards, publication practices, and the transparent communication of uncertainty should not depend upon which political party controls the executive branch.

Congress therefore has a legitimate oversight interest in obtaining clear answers to several questions:

• How many CDC employees have been lost since January 2025, by program and specialty?
• How many have been reinstated?
• Which scientific and surveillance functions have experienced measurable reductions in capacity?
• Which public-health databases have experienced interruptions, for what reasons, and for how long?
• What safeguards prevent political officials from altering epidemiological data for non-scientific reasons?
• How are conflicts of interest and scientific qualifications evaluated when advisory committees are reconstituted?
• What evidence supported the termination of the 22 BARDA mRNA investments?
• What has happened to the processing time and backlog of CDC-related FOIA requests since the April 2025 reorganization?
• What capabilities does CDC retain for detecting the next emerging infectious disease, zoonotic spillover, foodborne outbreak, environmental emergency, or bioterrorism threat?
• Which programs were reduced because of demonstrated redundancy or inefficiency, and which were reduced simply because personnel or funding became unavailable?
• What measurable standards will be used to determine whether the restructured CDC is succeeding?

These are questions that can be asked without assuming that either the administration or its critics are correct.

Conclusion

The available evidence does not justify declaring that the CDC has been destroyed or that it can no longer protect the American public. The agency remains operational. It has a permanent director, functioning disease-surveillance systems, major laboratories, active outbreak investigations, substantial vaccination programs, and continuing work in environmental health, chronic disease, injury prevention, and One Health. But neither should the documented disruption be minimized.

The CDC has experienced major personnel losses, abrupt leadership changes, restructuring of scientific advisory bodies, changes in vaccine policy, elimination of its independent FOIA office, and significant interruptions in the publication of some surveillance data. Former CDC directors from both Republican and Democratic administrations have publicly expressed concern that these changes could weaken American health security. The appropriate response to such evidence is neither partisan alarmism nor reflexive dismissal. It is rigorous oversight.

The United States cannot know when the next pandemic, emerging pathogen, foodborne outbreak, environmental emergency, or other public-health threat will arrive. It can, however, decide whether the institutions responsible for detecting such threats will have sufficient personnel, data, laboratories, scientific expertise, transparency, and operational independence when that day comes. 

That institutional question transcends party affiliation. These are appropriate subjects for congressional oversight because transparency is particularly important when an agency is undergoing major organizational change. It is ultimately a question of national preparedness, governmental accountability, and public safety.

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Editor’s Note: The opinions expressed here by the authors are their own, not those of impakter.com