As some of you might know, the CDC journal, Morbidity and Mortality Weekly Report (MMWR), was put on hiatus when Donald Trump and his team halted communications from the CDC on 23 January 2025, soon after taking office. Researchers, especially in public health, rely on MMWR for accurate and up-to-date information on infectious diseases and other health topics related to public health. The 2-week pause in publishing was the first time in MMWR‘s more than 60-year history that it was not published as scheduled.

The hiatus was due to a communications pause at federal health agencies issued by the Trump administration that went into effect on Tuesday, 21 January — it was supposed to end on 1 February. The pause applied to public communications including press releases, social media posts, and websites, as well as anything intended to be published in the Federal Register.

What was especially bad was that we were not getting updated information from the CDC about the H5N1 outbreaks, which many of us are carefully observing as it could become a serious health concern if it starts passing to humans more easily. Moreover, there is a new bird flu subtype, H5N9, that is also appearing in bird flocks, and we would like to be able to read about it in CDC publications.

Unfortunately, the MMWR will not be publishing anything about H5N1 at this time, although CDC officials claim that it is “in the pipeline.” I don’t mean to be cynical, but I’m guessing after the COVID pandemic caused so much trouble during the first Trump presidency, they don’t want anyone to worry about another pandemic. However, any potential pandemic will be much worse if we ignore what’s going on with H5N1.

What is going on with the MMWR?

On 7 February 2025, MMWR was published for the first time since 16 January with an article on emergency department usage during the Los Angeles wildfires and another article about toxic chemicals from the fires two years ago in Maui. There were no articles on H5N1 or H5N9.

According to KFF Health News, there were three articles about H5N1 that were supposed to be published on 23 January. The articles included one that discussed whether veterinarians who have been treating cattle infected with the virus became infected themselves and another that documented cases of people with the virus potentially infecting their pet cats.

The news about H5N1 has been getting more troubling over the past couple of weeks. The US Department of Agriculture’s Animal and Plant Health Inspection Service warned that a more severed genotype of the H5N1 virus, D1.1, that had only been detected in birds had now been detected in dairy cattle in Nevada. Before this, all dairy herds had the B3.13 genotype, which appeared to be associated with more mild forms of the disease.

As I mentioned before, another subtype of bird flu, H5N9, was detected in the USA for the first time in a duck farm in California where the H5N1 subtype had also been detected. The two subtypes together could lead to an event that includes reassortant viruses — not good for humans.

The MMWR must keep us up-to-date on what is going on with H5N1 and H5N9 so that public health officials can be prepared for the worst. We don’t know if either subtype is going to cause a pandemic, but the last thing we need is to not be informed with the best data possible.

Doctors, public health officials, first responders, and many others rely upon the CDC to provide the best information possible so that they can protect people’s lives. Without accurate and up-to-date information from the CDC, their jobs are harder.

I hope the H5N1 articles that are “in the pipeline” are published very soon. We all want to know what is happening.

Citations

• Beaucham CC, Zeiler R, Fent K, Chiu SK, Somerville N, Mayer A, Rinsky JL, Estill C. Notes from the Field: Serum Concentrations of Perfluoroalkyl and Polyfluoroalkyl Substances Among First Responders to the Maui Wildfires – Hawaii, September 2023. MMWR Morb Mortal Wkly Rep. 2025 Feb 6;74(3):35-39. doi: 10.15585/mmwr.mm7403a1. PMID: 39913327; PMCID: PMC11801521.
• Kajita E, Chang K, de Leon V, Moss W, Lim M, Balter S, de St Maurice A. Notes from the Field: Emergency Department Use During the Los Angeles County Wildfires, January 2025. MMWR Morb Mortal Wkly Rep. 2025 Feb 6;74(3):40-42. doi: 10.15585/mmwr.mm7403a2. PMID: 39913325; PMCID: PMC11801522.

As some of you might know, the CDC journal, Morbidity and Mortality Weekly Report (MMWR), was put on hiatus when Donald Trump and his team halted communications from the CDC on 23 January 2025, soon after taking office. Researchers, especially in public health, rely on MMWR for accurate and up-to-date information on infectious diseases and other health topics related to public health. The 2-week pause in publishing was the first time in MMWR‘s more than 60-year history that it was not published as scheduled.

The hiatus was due to a communications pause at federal health agencies issued by the Trump administration that went into effect on Tuesday, 21 January — it was supposed to end on 1 February. The pause applied to public communications including press releases, social media posts, and websites, as well as anything intended to be published in the Federal Register.

What was especially bad was that we were not getting updated information from the CDC about the H5N1 outbreaks, which many of us are carefully observing as it could become a serious health concern if it starts passing to humans more easily. Moreover, there is a new bird flu subtype, H5N9, that is also appearing in bird flocks, and we would like to be able to read about it in CDC publications.

Unfortunately, the MMWR will not be publishing anything about H5N1 at this time, although CDC officials claim that it is “in the pipeline.” I don’t mean to be cynical, but I’m guessing after the COVID pandemic caused so much trouble during the first Trump presidency, they don’t want anyone to worry about another pandemic. However, any potential pandemic will be much worse if we ignore what’s going on with H5N1.

What is going on with the MMWR?

On 7 February 2025, MMWR was published for the first time since 16 January with an article on emergency department usage during the Los Angeles wildfires and another article about toxic chemicals from the fires two years ago in Maui. There were no articles on H5N1 or H5N9.

According to KFF Health News, there were three articles about H5N1 that were supposed to be published on 23 January. The articles included one that discussed whether veterinarians who have been treating cattle infected with the virus became infected themselves and another that documented cases of people with the virus potentially infecting their pet cats.

The news about H5N1 has been getting more troubling over the past couple of weeks. The US Department of Agriculture’s Animal and Plant Health Inspection Service warned that a more severed genotype of the H5N1 virus, D1.1, that had only been detected in birds had now been detected in dairy cattle in Nevada. Before this, all dairy herds had the B3.13 genotype, which appeared to be associated with more mild forms of the disease.

As I mentioned before, another subtype of bird flu, H5N9, was detected in the USA for the first time in a duck farm in California where the H5N1 subtype had also been detected. The two subtypes together could lead to an event that includes reassortant viruses — not good for humans.

The MMWR must keep us up-to-date on what is going on with H5N1 and H5N9 so that public health officials can be prepared for the worst. We don’t know if either subtype is going to cause a pandemic, but the last thing we need is to not be informed with the best data possible.

Doctors, public health officials, first responders, and many others rely upon the CDC to provide the best information possible so that they can protect people’s lives. Without accurate and up-to-date information from the CDC, their jobs are harder.

I hope the H5N1 articles that are “in the pipeline” are published very soon. We all want to know what is happening.

Citations

• Beaucham CC, Zeiler R, Fent K, Chiu SK, Somerville N, Mayer A, Rinsky JL, Estill C. Notes from the Field: Serum Concentrations of Perfluoroalkyl and Polyfluoroalkyl Substances Among First Responders to the Maui Wildfires – Hawaii, September 2023. MMWR Morb Mortal Wkly Rep. 2025 Feb 6;74(3):35-39. doi: 10.15585/mmwr.mm7403a1. PMID: 39913327; PMCID: PMC11801521.
• Kajita E, Chang K, de Leon V, Moss W, Lim M, Balter S, de St Maurice A. Notes from the Field: Emergency Department Use During the Los Angeles County Wildfires, January 2025. MMWR Morb Mortal Wkly Rep. 2025 Feb 6;74(3):40-42. doi: 10.15585/mmwr.mm7403a2. PMID: 39913325; PMCID: PMC11801522.