Eric Escobar
eresc79.bsky.social
Eric Escobar
@eresc79.bsky.social
PhD, Structural Biologist and Protein Engineer with 14+ years of experience engineering molecules.

Thoughts and views here are my own.
Collectively, these data indicate that the virus detected in this pediatric case is very similar to the majority of other influenza A(H5N1) viruses detected in the United States and bears no signs of concerning mutations. 9/9
December 10, 2024 at 10:22 PM
Lastly, the sequence data confirmed that the virus from this case is not closely related to the virus that caused severe illness in a human in British Columbia, Canada. 8/
December 10, 2024 at 10:22 PM
The PB2 and PB1 genes did not have genetic changes associated with mammalian adaptation, nor were there any genetic changes identified in NA sequence data that have been associated with reduced susceptibility to neuraminidase inhibitors, such as oseltamivir. 7/
December 10, 2024 at 10:22 PM
Epidemiologic and environmental investigations did not clearly identify a possible source of exposure. Given that additional sequence data from the case could not be generated, it is unlikely that the source of the child's exposure will be identified. 6/
December 10, 2024 at 10:22 PM
Although the genetic data generated were insufficient to classify the virus as a specific genotype, the NA and NP sequences shared close nucleotide identity and phylogenetic clustering with NA and NP genes from recent B3.13 viruses detected in California in humans, dairy cattle and poultry. 5/
December 10, 2024 at 10:22 PM
Upon obtaining full-length NA and NP genes, CDC was able to perform a comprehensive phylogenetic analysis, which showed that the virus was very similar to viruses detected in both dairy cattle and poultry as well as to A(H5N1) viruses from previous human infections in dairy workers in California. 4/
December 10, 2024 at 10:22 PM
The initial sequence analysis, which was based on short fragments of the HA and NA genes, indicated that the virus was a clade 2.3.4.4b A(H5N1) virus similar to viruses causing outbreaks in dairy cattle and poultry in the United States. 3/
December 10, 2024 at 10:22 PM
By employing nucleic acid enrichment techniques, viral RNA sequence was generated for: full-length neuraminidase (NA) and nucleoprotein (NP) genes and partial hemagglutinin (HA), polymerase basic 2 (PB2), and polymerase basic 1 (PB1) genes. 2/
December 10, 2024 at 10:22 PM
Thanks for the thread and congratulations for the wonderful work!

Somehow the link to the paper didn't work for me, but I found it and here it is in case others have problems also

www.nature.com/articles/s41...
Cancer cells impair monocyte-mediated T cell stimulation to evade immunity - Nature
Inflammatory monocytes are identified as important players in T cell restimulation in the tumour microenvironment.
www.nature.com
November 27, 2024 at 8:01 PM
Ok, those were the main points I gathered. You can listen to the whole press conference on the YT link.

I will post later a more scientific explanation on the mutations and MOA in layman terms.
November 26, 2024 at 7:52 PM
Q. Was the kid in school?

DBH: The kid was not in school for the period when he was infectious.
November 26, 2024 at 7:48 PM
Q. What is special about the mutations?

DBH: Some mutations can allow the virus to bind receptors present deep in the lungs so people that contract the virus could get sicker. This is an area of active research.
November 26, 2024 at 7:48 PM
Q. What are we doing to prevent or prepare for a new pandemic?

DBH: Some cases in pigs have been seen. They're surveying other animals. It's also good if people get their flu shot to reduce the risk of getting co-infected with multiple strains that can allow the virus to become more transmissible.
November 26, 2024 at 7:45 PM
Q. Any long term consequences for the sick boy?

DBH: We don't know, although there are some positive signs that he might be starting to recover.
November 26, 2024 at 7:41 PM
Q. Investigation is closed. Should it stay open?

DBH: It is closed for now. They investigated all the leads and everything tested negative. Once the kid recovers and can talk to investigators they might reopen the investigation if there are new leads.
November 26, 2024 at 7:39 PM
Q. Are you concerned we might see more cases?

DBH: It is a very rare event. So far only one case has been seen. They are working with poultry workers to prevent more cases, and so far no cases from workers here in BC. The data suggest that the virus does not infect humans easily.
November 26, 2024 at 7:38 PM
Q. What made the infection so severe in this child?

DBH: The mortality in children in other places is high. They also found mutations in the virus that potentially makes it better fit for humans, so this could also be the cause for more severe symptoms.
November 26, 2024 at 7:36 PM
Q. Could the dog be the source?

DBH: Extensive testing on the dog didn't reveal a positive test, so as far as testing the dog never had #H5N1. They still think that it came directly from wild birds or another intermediary animal.
November 26, 2024 at 7:35 PM
Q. A case in California. Are we more concerned about how the virus is adapting to humans?

DBH: That is another rare event. The genome of that case is not yet available. The authorities in the US are investigating.
November 26, 2024 at 7:31 PM
Q. Any pre-existing health conditions on the kid who is very sick?

DBH: No, the kid was healthy. Researchers are looking for clues in the sequence of the virus to understand why the kid was so sick.
November 26, 2024 at 7:29 PM
The genomic sequence of the virus in the kid is closest to that detected in wild geese in the Fraser valley in October, and not to that of poultry outbreaks or that in the dairy outbreaks. 4/
November 26, 2024 at 7:26 PM
Contact tracing has not resulted in any other positive case. The family dog was sick, but it tested negative, and other animals that came in contact with the dog tested negative 3/
November 26, 2024 at 7:26 PM
The kid remains in intensive care.

Investigation on the source is now closed. There were dozens of health care workers and family members exposed, but all of them tested negative. 2/
November 26, 2024 at 7:26 PM