The internet's buzzing with outrage over a September 2025 npj Viruses study claiming the CDC cooked up a new H5N1 bird flu strain in its Atlanta labs, complete with mutations (P136S and A156T) that make it a ninja at dodging the immune system. Critics, like Jon Fleetwood, scream "gain-of-function" and point to the study's admission that A156T adds a sugar shield, slashing antibody effectiveness by up to 99% in some tests. With COVID-19's lab-leak shadow lingering (backed by FBI, DOE, and Congress), this produces fears of reckless federal labs brewing the next pandemic in just six business days.
The npj Viruses paper, led by CDC's Li Wang et al., didn't conjure H5N1 from thin air. It started with a 2024 Missouri patient's H5N1 sample, which had two odd mutations (P136S, A156T) in its haemagglutinin (HA) protein, the virus's key to infecting cells. Unable to grow a live virus, the team synthetically grafted these onto a cattle-outbreak strain's backbone in Atlanta's BSL-3E labs. The big deal? A156T added an N-linked glycosylation site at residue 154, a sugar coat that shields the virus from antibodies, cutting haemagglutination inhibition (HI) titers by at least 4-fold and neutralising activity by up to 99% for some antisera (e.g., TX37, MI90). Translation: The mutant virus was harder for immune systems to spot.
This was no accident, the CDC aimed to study how these mutations, seen in a real-world case, might hobble vaccines or treatments.
The CDC's stated goal was straightforward: Understand H5N1's evolution to stay ahead of a potential pandemic. H5N1's 50%+ human mortality rate (648 deaths/1,242 WHO cases, 1997-2024) makes it a scary prospect, even if rare in humans. The Missouri case, part of 2024's dairy worker/cattle outbreaks, raised red flags with A156T's immune dodge, echoing fears of antigenic drift seen in past flu pandemics. By recreating it, the CDC aimed to test vaccine efficacy and inform stockpiles, critical since H5N1's clade 2.3.4.4b is spreading in birds and mammals.
The CDC's opacity and timing. Post-COVID, with 69% of Americans (per Rasmussen 2023) believing a lab leak likely, trust in federal labs is shaky. Trump's September 2025 UN call to ban bioweapons research (post-Wuhan scrutiny) clashes with this study's optics, published the same month. X posts explode with "CDC bioterror" takes, citing the 6-day synthesis as proof of reckless speed. Why no public heads-up on such sensitive work? And why no clear GOF disclaimer, given 2014-17 bans on similar flu tweaks?
This is one more disaster waiting to happen from gain-of-function research.
https://jonfleetwood.substack.com/p/cdc-creates-new-bird-flu-virus-with