The Centers for Disease Control and Prevention has merged its Influenza Division and its Coronavirus and Other Respiratory Diseases Division into a single Influenza and Respiratory Viruses Division, according to a notice published in the Federal Register on Wednesday. The reorganization was approved by the Secretary of Health and Human Services on August 18 and took effect on September 4.

The notice is administrative in form and substantive in content. It states that the National Center for Immunization and Respiratory Diseases has "consolidated offices, retitled divisions and branches" and modified mission and function statements, then sets out the new structure and the functions each component retains. It is signed by Health and Human Services Secretary Robert F. Kennedy Jr.

For readers who follow wildlife disease rather than clinical medicine, the relevant detail is what stayed inside the merged division. The functions listed for the new branches include characterization of animal viruses, pandemic risk assessment for novel respiratory viruses, and development of pre-pandemic candidate vaccine viruses. Those are the capabilities that sit at the interface between wild bird surveillance, poultry and dairy outbreaks, and human public health, and they now report through one division rather than two.

Two Divisions Consolidated into One

Under the reorganization, the former Influenza Division and the former Coronavirus and Other Respiratory Diseases Division cease to exist as separate units. The new Influenza and Respiratory Viruses Division consists of an Office of the Director and five branches: Virology and Laboratory Surveillance; Respiratory Virus Detection and Immunology; Surveillance, Epidemiology, and Modeling; Public Health Interventions; and Emerging Viral Respiratory Threats.

The notice describes the division's mission as preventing disease, disability and death through the prevention and control of seasonal, epidemic and pandemic respiratory viral diseases, including influenza. Five listed activities cover monitoring infection and disease patterns, conducting surveillance and response with state, local and international partners, identifying and characterizing viruses to improve detection and countermeasures, designing and evaluating prevention strategies, and applying research to prevention and control policy.

The notice also states that all delegations and redelegations of authority made to officials of the affected components continue in them or their successors, provided they are consistent with the reorganization. It amends the Department of Health and Human Services statement of organization, functions and delegations, which was last amended in September 2024.

Branch Functions Named in the Notice

The Virology and Laboratory Surveillance Branch carries the heaviest laboratory load. Its listed functions include antigenic, phenotypic, genotypic, structural and evolutionary characterization of human and animal viruses and of novel emerging viruses with pandemic potential. It performs genetic and antigenic testing supporting risk assessments of seasonal and novel viruses, provides expert guidance and technical support on vaccine virus selection and other medical countermeasures, develops and evaluates seasonal and pre-pandemic candidate vaccine viruses, and trains external laboratories that perform molecular detection and genetic characterization of influenza and other respiratory viruses.

The Respiratory Virus Detection and Immunology Branch performs immunologic and genetic surveillance, examines immunity against respiratory viruses, provides laboratory support during outbreaks and clusters, contributes expert input to respiratory virus vaccine selection, and conducts immunologic and virologic pandemic risk assessment of novel respiratory viruses.

The Surveillance, Epidemiology, and Modeling Branch runs national and sentinel surveillance, epidemiologic studies, modeling and forecasting, and provides technical support to state and local health departments. The Public Health Interventions Branch designs and evaluates prevention strategies including vaccination, treatment and non-pharmaceutical measures.

The Emerging Viral Respiratory Threats Branch is the component whose listed scope is global. It supports enhanced global surveillance for respiratory viruses, conducts surveillance, program evaluation, research and modeling to improve understanding of respiratory viruses worldwide, advances rapid detection and response to emerging and novel respiratory viruses outside the United States, promotes prevention and control globally, and supports global outbreak response and pandemic preparedness.

Animal Virus Work Stays Inside the New Structure

The functions that matter most to wildlife and agricultural reporting are named explicitly rather than left implied. Characterization of animal viruses, pandemic risk assessment for novel respiratory viruses and the development of pre-pandemic candidate vaccine viruses all appear in the branch descriptions, which means the reorganization moved these capabilities rather than removing them from the published function statements.

That matters because the surveillance system they connect to is not centralized in one agency. Wild bird and poultry detections of highly pathogenic avian influenza are reported by the U.S. Department of Agriculture through its avian influenza detections pages, which draw on samples from federal wildlife agencies and state fish and game departments. Human risk assessment sits with CDC, which maintains its own situation summary for A(H5) bird flu and, since mid-2025, points readers to the agriculture department for animal detection data.

Laboratory characterization is the link between those systems, the step that turns a positive sample into an assessment. Determining whether a virus recovered from a wild goose or a dairy herd has changed in ways that affect transmissibility, or whether existing candidate vaccine viruses still match, is the work described in the branch functions. Readers tracking avian influenza should understand that the underlying reporting streams have not changed. What changed is which CDC division houses the analysis.

Timing, Open Questions and the Public Record

The effective date places the change immediately before the season the division monitors. Respiratory virus activity in the United States typically rises through the fall, and fall waterfowl migration is the period when wild bird detections of avian influenza have historically increased across North American flyways. Both are seasonal patterns rather than forecasts, and neither is a prediction about this particular autumn.

The notice does not answer several questions that reporters and researchers will want addressed. It does not state staffing levels, budget allocations or whether any positions were eliminated. It does not describe how the merged division will divide work that previously sat in two separate reporting lines, and it does not list a transition timeline beyond the effective date. It is a structural notice and should be read as one.

Readers who want the primary source can review the full text through the Federal Register or the official printed version. Current program information remains available through the National Center for Immunization and Respiratory Diseases.

The bottom line is narrow and factual. CDC has combined two divisions into one, has named five branches including one focused on emerging respiratory threats outside the United States, and has kept animal virus characterization, pandemic risk assessment and vaccine strain support in the published function statements. Anyone tracking avian influenza in wild birds should continue using the agriculture department's detection records and the CDC situation summary. Nothing in the notice changes how those data are reported or where the public finds them.

What Readers Want to Know

What exactly did CDC change? It merged the Influenza Division and the Coronavirus and Other Respiratory Diseases Division into one Influenza and Respiratory Viruses Division with an Office of the Director and five branches.

When did it take effect? The reorganization was approved by the Secretary of Health and Human Services on August 18 and became effective on September 4. The notice published on September 9.

Is the new Emerging Viral Respiratory Threats Branch focused on the United States? No. The functions listed for that branch center on global surveillance, rapid detection of novel respiratory viruses outside the United States, and international outbreak response.

Does this affect avian influenza reporting? Not in terms of where data comes from. Wild bird and poultry detections are still reported by the U.S. Department of Agriculture, and CDC still maintains its own human risk assessment.

Does the notice say anything about staffing or budget? No. It describes structure and function statements only, and does not address personnel numbers, funding or position eliminations.

Where can I read the original document? Through the Federal Register document page or the official printed version on govinfo. Both are free and public.

Who signed the notice? Health and Human Services Secretary Robert F. Kennedy Jr., under the authority governing departmental organization statements.