David Bacsik

7/ Clinicians: The H5 subtyping PCR is available to order now through UW Medicine: testguide.labmed.uw.edu/view/FLUH5

Validation of H5 influenza virus subtyping RT-qPCR assay and low prevalence of H5 detection in 2024-2025 influenza virus season A sustained outbreak of H5N1 influenza virus among wild fowl and domestic livestock has caused more than 70 zoonotic infections in humans in the United States, including one death. The Centers for Dis...

6/ Read more in our manuscript from the
Greninger Lab
at UW Virology
: medrxiv.org/cgi/content/.... Many people contributed to this work, including
@margaretgracemills.bsky.social, Ailyn Perez-Osorio, and
@pavitrarc.bsky.social.

5/ The CDC recommends subtyping all hospitalized flu A+ cases. With H5N1 still circulating widely in birds & cattle, monitoring remains critical—especially for patients with close animal contact, who face the highest risk.

4/ This suggests that, in Seattle, the 2024-2025 flu season has been driven by seasonal strains, with no H5N1 detected among this cohort of patients with lab-confirmed influenza A infections.

3/ So far, none of the samples tested have been H5-positive. All sequenced samples contained seasonal H3N2 or H1N1 viruses.

2/ In Dr. Alex Greninger’s lab at UW Virology, we developed a clinical RT-qPCR assay for H5 subtyping. We used it to differentiate seasonal influenza A infections from subtype H5 infections during Seattle’s 2024-2025 influenza season.

1/ How has H5N1 affected this year’s flu season in Seattle? Despite ongoing outbreaks in birds & cattle nationally, we detected zero H5N1 cases in 675 influenza A-positive specimens tested at UW Medicine.

RSV F evolution escapes some monoclonal antibodies but does not strongly erode neutralization by human polyclonal sera Vaccines and monoclonal antibodies targeting the respiratory syncytial virus (RSV) fusion protein (F) have recently begun to be widely used to protect infants and high-risk adults. Some other viral pr...

In study led by @csimonich.bsky.social & Teagan McMahon, we quantify antigenic evolution of RSV F

Important because:

1️⃣ RSV top cause of infant hospitalization in USA

2️⃣ New antibodies & vax can prevent hospitalizations

3️⃣ Will virus evolution erode their efficacy?

www.biorxiv.org/content/10.1...

I agree with Scott. This is important because:

1. This shows that cattle are susceptible to other H5N1 viruses, not just B3.13.
2. D1.1 viruses are currently transmitting really efficiently through wild birds in North America, and are very widespread.
...