Referral (NEJM): Autoantibodies against Type I Interferons and Death from H7N7 Avian Influenza

[Michael Coston]

Referral (NEJM): Autoantibodies against Type I Interferons and Death from H7N7 Avian Influenza​

AutoAb development in population
credit Human autoantibodies against type I
interferons in severe viral disease

#19,413

We've a fascinating correspondence - published yesterday (Nov 11th) in the NEJM - which links a relatively rare autoimmune dysfunction (autoantibodies against Type I Interferons) to increased severity of novel flu infection.

The authors hypothesize that those with this condition could potentially act as “patients zero” in emerging viral pandemics.

Since this correspondence is not open access, I'm only able to give some background and a brief synopsis. Those already familiar with the events of the 2003 H7N7 outbreak, and the recent discoveries surrounding this autoimmune condition, may prefer to proceed directly to the link below.

Autoantibodies against Type I Interferons and Death from H7N7 Avian Influenza
Published November 11, 2026
N Engl J Med 2026;395:1963-1965
DOI: 10.1056/NEJMc2608446
VOL. 395 NO. 19 Copyright © 2026

For those preferring a review:

In 2003, the Netherlands saw an outbreak of H7N7 that resulted in the loss of 30 million birds across 1,000 farms, and saw scores of mild human infections and the death of a veterinarian (see Eurosurveillance Human-to-human transmission of avian influenza A/H7N7, The Netherlands, 2003).

Another analysis, performed by the RIVM (Ministry of Health) found the spread of the virus to be much greater than originally reported, citing as many as 1,000 human infections (see Executive summary Avian Flu Epidemic 2003: Public health consequences).

Both reports cited likely human-to-human transmission, with the RIVM study finding ` . . 58.9% of the family contacts of persons having direct exposure to poultry had a measurable response in the HI test.'

Most of these cases reported mild symptoms; primarily conjunctivitis. A minority reported mild-or-moderate flu-like symptoms (often in conjunction with conjunctivitis), and one patient died.

While nowhere as deadly to humans as H5N1 or H7N9, this H7N7 outbreak serves as a cautionary tale on the susceptibility of humans to novel influenza. It also raises questions about the wide spectrum of outcomes from novel flu infection.

Relatively recently a rare immune dysfunction - autoantibodies against type I interferons - has been tagged as a likely determinant of severity in viral infections.

Six months ago, a review article in Current Opinion in Virology (Human autoantibodies against type I interferons in severe viral disease by Groen & Hale) reported:

Highlights

• AutoAb development is influenced by age, genetics, immune tolerance, and infections.

• IFN-I autoAbs heighten risk for severe infections and live-vaccine adverse events.

• Targeted diagnostic screening for IFN-I autoAbs could benefit certain individuals.

• Understanding autoAb mechanisms will help devise potential therapeutic strategies.

While first discovered in the early 1980s, it wasn't until COVID that AutoAbs impact on viral infections was really appreciated (see Nature Human genetic and immunological determinants of critical COVID-19 pneumonia).

All of which brings us to the NEJM correspondence, where the authors went back and tested stored serum from 35 patients from the 2003 H7N7 outbreak, including the 58 y.o. veterinarian who died.

They found the fatal case had autoantibodies neutralizing interferon-α, -ω, and -β, while 2 of the remaining 34 mild cases had autoantibodies neutralizing interferon-β only.

Since antibodies against all three subtypes are rare in people under 60, the authors say this is unlikely to be by chance. Strengthening their case, the fatal H5N1 case in Louisiana in early 2025 carried IFN-I autoAbs.

Autoantibodies neutralizing type I IFNs in a fatal case of H5N1 avian influenza

Qian Zhang Corresponding Author , Taylor S. Conrad , Marcela Moncada-Velez , Kaijun Jiang ,Anastasija Cupic , Jonathan Eaton , Kimberley Hutchinson ,Adrian Gervais ,Ruyue Chen , Anne Puel , Paul Bastard , Aurelie Cobat ,Thersa Sokol , RyanA. Langlois ,Lisa Miorin , Adolfo García-Sastre ,John A. Vanchiere , Jean-Laurent Casanova Corresponding Author

Author and Article Information
J Exp Med (2026) 223 (3): e20251962.
https://doi.org/10.1084/jem.20251962

While it is well established that avian flu viruses have a hard time establishing themselves in humans, and that human-to-human transmission is uncommon, this rare autoimmune condition could provide a foothold for novel viruses like H5N1, H7N7, and H9N2 to adapt to humans.

At least that's the theory. Admittedly, one based on limited evidence.

But if it turns out to be correct, it becomes even more imperative that we take steps to prevent spillovers (PPEs, seasonal flu vaccines to prevent coinfection and reassortment, etc.), and to treat even mild cases as potential public health threats.

Policies which, based on recent anecdotal reports (see Newsweek Farm Workers Sound Alarm on Underreported Bird Flu Numbers), still appear to be lacking.



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