David Bacsik
dbacsik.bsky.social
David Bacsik
@dbacsik.bsky.social
Tracing viruses in Perú w/ Dr. Pablo Tsukayama @ UPCH and Dr. Alex Greninger @ UW Virology

Before: Developing single-cell methods for influenza biology w/ @jbloomlab.bsky.social

MD/PhD Student @ University of Washington
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.
March 19, 2025 at 2:20 PM
Reposted by David Bacsik
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...
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...
www.biorxiv.org
March 12, 2025 at 10:31 PM
Reposted by David Bacsik
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.
...
This is big because:
1. This is evidence of a 2nd avian-->cattle H5N1 introduction.
2. The D1.1 genotype was found in the severe case in British Columbia and the deadly case in Louisiana. It is possible that this genotype has an easier time adapting to human cells.

www.statnews.com/2025/02/05/u...
USDA milk testing shows different strain of H5N1 bird flu in Nevada dairy herds
The USDA said four Nevada dairy herds were infected with an H5N1 bird flu strain that has circulated in wild birds, making prospects for containment in cows appear dim.
www.statnews.com
February 5, 2025 at 8:00 PM