Marios Koutsakos

Immunodominance is a poor predictor of vaccine-induced T follicular helper cell quality Our findings emphasise the importance of CD4+ T cell help for programming robust and durable humoural immunity, and provide crucial insights to guide the rational incorporation of favourable T cell ep...

🎉 Our new study of CD4 TFH quality is now online @ebiomedicine.bsky.social! We know that TFH are critical for germinal centres and antibody production, but want to understand whether all CD4 responses can be equally helpful to B cells.

www.thelancet.com/journals/ebi...

Are influenza B viruses really “human only”? New review synthesises evidence from serology & metagenomics for #IBV / IBV-like viruses in animals and aquatic hosts. One Health gaps remain. With @marioskoutsakos.viralvaxlab.com @duckswabber.bsky.social www.mdpi.com/1999-4915/17...

Molecular basis of influenza ribonucleoprotein complex assembly and processive RNA synthesis @science.org @yiweichang.bsky.social
www.science.org/doi/10.1126/...

Characterization of the glycoproteins of novel fish influenza B-like viruses Novel influenza-like virus sequences previously identified in fish and amphibians were found to cluster as a sister clade of influenza B viruses, but have thus far remained uncharacterized. We demonst...

Happy to be able to contribute to this very cool preprint
Characterization of the glycoproteins of novel fish influenza B-like viruses #glycotime #lovevirology @uu-cbdd.bsky.social www.biorxiv.org/content/10.1...

In unexposed adults, frequency of memory B cells with cross-reactive recognition of H5 + H7 low, & lower in unexposed vs humans w seasonal H1N1/H3N2 HA-specific B cells. Boosting B cell responses against HPAI following seasonal immunisation = sporadic.
👉 www.biorxiv.org/content/10.1...

Happy to finally share this work!

Check out the latest from @viralvaxlab.bsky.social postdoc Wen Shi Lee, developing monoclonal antibodies that neutralise the NL63 coronavirus!

Happy to report that Mitchell's paper on CD4 T cells and AIM assays is now available online at Science Advances!

www.science.org/doi/10.1126/...

Thanks to all our collaborators in @viralvaxlab.bsky.social and @thedohertyinst.bsky.social, including @assocprofashhaque.bsky.social lab

New preprint alert 🚨

My team and I are pleased to share our most recent story about how bacterial pathogen (Streptococcus pyogenes, Strep A) exposure induces antibody responses against glycan and protein antigens.

For paper: SSRN ssrn.com/abstract=519...
biorxiv : doi: doi.org/10.1101/2025...

Immune history shapes human antibody responses to H5N1 influenza viruses - Nature Medicine H5N1 strain-specific antibodies are higher in older individuals and correlate more with birth year than with age, suggesting that younger individuals are potentially more likely to benefit from H5N1 v...

Today @natmedicine.bsky.social published our study showing the older individuals born prior to 1968 have more antibodies that cross-react to #H5N1 relative to younger individuals. If H5N1 causes a pandemic, children will likely be the most susceptible. 1/2

www.nature.com/articles/s41...

Institut Pasteur du Cambodge on LinkedIn: The Institut Pasteur du Cambodge (IPC) is looking for: -… The Institut Pasteur du Cambodge (IPC) is looking for: - 𝐏𝐨𝐬𝐭𝐝𝐨𝐜𝐭𝐨𝐫𝐚𝐥 𝐑𝐞𝐬𝐞𝐚𝐫𝐜𝐡𝐞𝐫 – 𝐒𝐞𝐫𝐨𝐥𝐨𝐠𝐲 𝐚𝐭 𝐭𝐡𝐞 𝐇𝐮𝐦𝐚𝐧-𝐀𝐧𝐢𝐦𝐚𝐥…

The Virology Unit at IPC has 3 positions open in #OneHealth:

*Postdoc – Reconstructing Past Outbreaks

*Postdoc – Environmental Surveillance

*Clinical Manager

These aren’t just jobs. They’re front-row seats to global health in action. Ready?

tinyurl.com/57rvxcau

#ViroSky #IDSky 🦠🔬🧬🥼🧪

1/ Hot off the press in @jimmunol.bsky.social. We investigated how same side (ipsilateral) vs alternate side (contralateral) prime-boost vaccination impacts germinal center (GC) dynamics & antibody responses against SARS-CoV-2 spike in mice.💉🦠#immunology #vaccines @thedohertyinst.bsky.social

Modulation of germinal center and antibody dynamics via ipsilateral versus contralateral immunization against SARS-CoV-2 Abstract. Human clinical trials have reported immunological outcomes can differ between ipsilateral (same side) and contralateral (alternate sides) prime-b

New research from @thedohertyinst.bsky.social suggests that receiving multiple doses of a vaccine in the same limb leads to faster antibody development, an important strategy for providing #immunity quickly during a pandemic or disease #outbreak. #ReadTheJI #immunology

ow.ly/c28N50VeRGR

Antigenic map of H5 influenza viruses spanning their evolutionary history. 3 clusters (surprisingly few!) w no cross immunity. 6 key aa identified. 2344b, 2321a, 2344h in different clusters. Big jump in antigenicity from 234 to 2344b important finding.
👉 www.researchsquare.com/article/rs-6...

Negative-Strand RNA Virus meeting #NSV2025 registration is now open!
Visit www.negativestrandvirus.org/home

Influenza A virus rapidly adapts particle shape to environmental pressures - Nature Microbiology Quantitative flow virometry assay to measure the shape of viral particles under various conditions reveals that influenza virus infections dynamically tune shape distribution of progeny particles depe...

www.nature.com/articles/s41...

Polymerase mutations underlie adaptation of H5N1 influenza virus to dairy cattle and other mammals. In early 2024, an unprecedented outbreak of H5N1 high pathogenicity avian influenza was detected in dairy cattle in the USA. The epidemic remains uncontrolled, with spillbacks into poultry, wild birds...

Really proud to share our preprint describing early adaptation of H5N1 to US dairy cattle, and showing how these mutations enhance the ability of the virus to infect other mammals, such as pigs and humans.

With @influenzal.bsky.social @vidhid.bsky.social @drclairesmith.bsky.social and many more!

8/9 In short, we suggest in vitro stimulation activates ag-specific T cells, which secrete cytokines and activate Treg and Th17/22 cells. Without careful phenotyping, all of these cells can get picked up as AIM+, accounting for the Th17-like memory cells found in many virus-specific AIM datasets.

@viralvaxlab.bsky.social

Thanks @ausvirologysoc.bsky.social for a great meeting. Where else can you turn the evolution of flu A vs flu B strains as described by @marioskoutsakos.bsky.social into a dance move. Having Jenna Guthmiller here from the US was a highlight for me! See you all in Adelaide in 2026

A single mutation in bovine influenza H5N1 hemagglutinin switches specificity to human receptors In 2024, several human infections with highly pathogenic clade 2.3.4.4b bovine influenza H5N1 viruses in the United States raised concerns about their capability for bovine-to-human or even human-to-h...

I have a few brief thoughts on this just released Science paper on the adaptation potential of bovine #H5N1 HA. Its very good work by very good group at Scripps! Think people need to be cautious in assessing the actualized risk out of this one study. #influenza

www.science.org/doi/10.1126/...

Next up is Marios Koutsakos @marioskoutsakos.bsky.social who is presenting Antigenic evolution of the influenza B virus HA over 80 years of circulation in humans. Marios has apologised for only including one phylogenetic tree in his talk in this evolutionary virology session. #AVS12

I've made a starter pack for Aussie virologists joining Bluesky at #AVS12. Let me know if you would like to be added- please share 🤗

@ausvirologysoc.bsky.social

go.bsky.app/FgBEzfc

Virologist here - please add me too 🙏

could I be add to this too please - thank you

please add me too! Thanks!