H5N1 in dairy herds: a new variant raises more pandemic concerns

Ugh. Moo.

The news is increasingly hard to read, isn’t it? So much is being done that is harmful, destructive, and mean. But we need to keep up with it to some degree based on individual stress tolerance and current emotional state. For example I’m trying not to follow each and every H5N1 bird flu article — but there’s been some stuff happening this week that I think deserves highlighting. The following post draws from two articles I thought were excellent (one from Helen Branswell at STAT News, and the other from Dr. Carolyn Barber writing for Fortune).

I think the landscape of H5N1 avian influenza in the United States has taken a concerning turn with the discovery of a new variant in Nevada dairy herds last week. This development marks a significant shift in our understanding of the virus's ability to adapt and spread, with implications for both animal and human health.

Understanding the New Variant

The USDA recently confirmed that four dairy herds in Nevada have been infected with a different strain of H5N1 than the one that has been circulating in cows over the past year. This new variant, identified as genotype D1.1, is particularly noteworthy because it represents a separate spillover event from wild birds to cows. Unlike the previously dominant B3.13 genotype found in cattle, this D1.1 variant has been associated with more severe human infections, including a fatal case in Louisiana and a severe case in British Columbia.

As Dr. Daniel Griffin teaches on TWiV podcasts, we can remember the genotype nomenclatures this way:

• D as in more deadly

• B as in more benign.

Impact on Containment Efforts

This genotype D1.1 discovery in dairy herds has significant implications for containment strategies. The USDA's previous assumption that the outbreak could be controlled through interstate testing requirements and natural burnout now appears overly optimistic. The virus's demonstrated ability to make multiple successful jumps from wild birds to cattle suggests that containment will be more challenging than initially thought. The presence of H5N1 in wild bird populations across North America creates ongoing opportunities for new spillover events.

Public Health Implications

The public health community is particularly concerned about the D1.1 variant's potential for human infection. Research has shown that during human infections, this variant has begun acquiring mutations that could enhance its ability to infect human respiratory cells. While the CDC maintains that the general public's risk remains low, individuals with prolonged exposure to infected animals or contaminated environments face increased risk.

All of this should compel a phone call to our Senators, reminding them that RFK Jr. will be a disaster. Especially if Republican they should have the courage to vote “no” against his nomination to lead HHS. Recall that RFK Junior has called for no more investment in infectious disease research for 8 years. I’m also making calls to Dr. Bill Cassidy (R). He is a Republican who is at least flinching with respect to this nomination, though he gave a thumbs up to Kennedy’s nomination, allowing it to come out of Senate committee for a general vote. Give him a call, too. Tell him to uphold both his oath to medicine and his oath to the country:

• (225) 929-7711 or contact here.

• Your state’s senator contact information can be found here.

I agree with Dr. Jeffrey Flier:

“Over the edge. Down the rabbit hole. Completely insane,” Dr. Jeffrey Flier, a professor and former dean of Harvard Medical School, posted on X in response to Kennedy’s nomination. “Would not have believed this possible until right now. Completely independent of politics, this must be seen as unacceptable in 2024.”

And then there’s this I just read this morning:

The NIH, the nation’s premier funder of biomedical research, announced Friday that it will immediately slash support for “indirect costs” paid to universities, medical centers, and other research grant recipients, funding that the nation’s science enterprise relies on for basic operating costs.

It’s beyond infuriating. It’s self-destructive.

Future Pandemic Potential

Ok back to the science stuff. As we were saying, the emergence of this new variant represents a critical moment in the evolution of H5N1. Several factors make this situation particularly concerning from a pandemic perspective:

1. The virus has again demonstrated the ability to adapt to new mammalian hosts, with multiple successful jumps from birds to cattle.

2. The D1.1 variant appears more capable of causing severe disease in humans than previous strains affecting cattle.

3. The widespread presence of the virus in wild bird populations creates numerous opportunities for further evolution and adaptation.

4. Current testing and surveillance systems may be insufficient to detect and track new variants quickly enough.

Necessary Actions

To address these growing concerns, experts recommend several key measures:

• Implementing more rigorous testing protocols across dairy operations

• Accelerating the development and production of H5N1 vaccines for both animals and humans

• Enhancing biosecurity measures on farms

• Strengthening surveillance systems for both animal and human cases

• Ensuring proper protective equipment for dairy workers and others in high-risk occupations

But what else can you personally do? I addressed this back in December. This post has now been viewed 10K times. Not bad.

The public health community must remain vigilant and prepared to respond quickly to any signs of increased human-to-human transmission, which would signal a potential pandemic threat. They are demoralized right now.

This ongoing situation also represents one of the most significant challenges in the interface between animal and human health, requiring continued cooperation between agricultural, veterinary, and public health sectors to manage effectively.

I also included a study about regular flu shots and H5N1 at the end of my last Covidlandia post. In case you couldn't make it to the end, here it is:

Will regular flu shots help us in the event of an H5N1 bird flu pandemic?

With egg prices soaring, and hens everywhere being slaughtered, it is a grim time to be a chicken.

I’d like to add this bit of real world evidence to answer the question of whether regular flu shots might offer us some cross-protection against bird flu.

A study published in mBio investigated whether seasonal flu vaccines could provide protection against potential avian influenza (H5N1 and H7N9) pandemics. Researchers analyzed blood samples from 135 Spanish individuals across three age groups, before and after receiving seasonal flu vaccines. They found that baseline protection against these avian flu strains was very limited in the population. However, seasonal vaccination did increase protective antibody levels against H5N1 in about 15% of younger participants, though this protection largely disappeared after six months.

Examining the data from the paper, for H5N1 protection after seasonal vaccination:

• Younger group (born 1978-1997): 15.0% developed protection

• Middle group (born 1968-1977): 12.2% developed protection

• Older group (born 1925-1967): 0% developed protection

The older group (G1) showed no seroconversion response against H5N1 after vaccination, which the authors suggest might be due to immunosenescence (age-related decline in immune function). This is particularly noteworthy since the older group actually received a high-dose version of the quadrivalent flu vaccine, while the younger groups received a standard-dose version.

Overall the study suggests that seasonal flu vaccines could serve as a shaky first line of defense during the early stages of an avian flu pandemic when specific vaccines are not yet available, but would need to be followed by strain-specific vaccines for better protection. Often younger people are more severely effected by influenza pandemics, so a flu shot would be especially important for them (?).

Also be aware that in the final days of the Biden/Harris administration, Moderna was awarded $590 million to develop mRNA vaccines targeting potential pandemic flu threats, particularly H5N1 and H7N9 avian influenza strains. The project includes clinical trials for multiple flu variants and aims to enhance pandemic preparedness using mRNA technology. Thank you for your service.

PS - maybe tamiflu will help.

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OK, that’s all I can take for today. Off to make some chili for the Super Bowl. Eagles 28, KC 24. Saquon Barkley MVP. But I already feel guilt about watching the injuries and thousands of cumulative head traumas. I would be totally happy if they switched to playing flag football.

I would be totally happy not thinking about the real world for the rest of the day. I’m working on a GLP-1 post for you, too. Take good care.

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Photo credit by Jonas Koel on Unsplash