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Jesse Erasmus

@jesseerasmus.bsky.social
2.3K followers 1.1K following 176 posts

Director of Virology at HDT Bio. Developing RNA platform for emerging infectious diseases. 🇿🇦🇰🇷

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Jesse Erasmus @jesseerasmus.bsky.social · 03/09/2026
Excited to contribute to this effort. Solving this problem will require multiple shots on goal. We at HDT Bio will be contributing our experience in manufacturing of long RNA molecules and simplified formulation with LION to create safe, yet potent, personalized drugs. More information to come soon!
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Jesse Erasmus @jesseerasmus.bsky.social · 21/05/2026
Excited that our work to mature a new vaccine and therapeutics platform, with application of the technology to an important tick borne disease, is getting some recognition. Of course, where the rubber meets the road is in the data. More to come on that soon! www.prnewswire.com/news-release...
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
12/ Takeaway: this is a full RNA→RNA pipeline: RNA immunization → VHH discovery → structural validation → RNA encoding → in vivo efficacy Compact antibody formats + RNA delivery are functionally enabling. Shout out to Eddie Hodge and Jacob Archer who did a lot of the heavy lifting here!
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
11/ In a mouse challenge model, repRNA-delivered VHH-Fc significantly reduced viral titers (lung + nasal cavity) in a dose-dependent manner compared to an irrelevant repRNA-VHH control, outperforming VHH monomer or dimeric IgA formats
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
10/ We then closed the loop with RNA delivery. repRNA encoding VHH or VHH-Fc and delivered with LION via IM route demonstrated: 1) rapid in vivo expression, 2) detectable serum levels within a day, and 3) functional neutralization activity
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
9/ With the Kuhn lab, we obtained a 1.4 Å structure: G12 VHH binds the VP1 canyon region, engaging BC, EF, and GH antigenic loops near a conserved functional site, where the bulky Fc domain likely contributes to steric hindrance. The spheres in the map below represent the binding footprint of G12
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
8/ Addition of the IgG1 Fc domain surprisingly increased breadth with sub 0.3nM IC50 measured across all 6 subclades.
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
7/ However, the monovalent G12 VHH only exhibited strong neutralization against the B1 and B2 subclades:
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
6/ High-throughput screening of phage libraries identified multiple binders and a subset of neutralizers, with G12 emerging as a standout.
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
5/ To build the front end of the workflow: We worked with the Shoemaker lab at Tufts University to immunize alpacas with a hexavalent vaccine (each encoding EV-D68 VLPs) covering the 6 subclades of EV-D68, inducing cross-clade neutralizing responses.
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
4/ To capitalize on that finding, we established a VHH discovery workflow to support the development of repRNA-encoded VHHs using EV-D68 as a model pathogen. We recently completed a full vaccine development campaign for that virus described here: www.science.org/doi/abs/10.1...
science.org
A self-amplifying RNA vaccine prevents enterovirus D68 infection and disease in preclinical models
A self-amplifying RNA vaccine for enterovirus D68 elicits neutralizing antibodies in mice and nonhuman primates and protects mice from disease.
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
3/ In that prior work, we identified that canonical IgG formats are not ideal for RNA expression in vivo. Here we show that removing the CH1 domain (moving to compact formats like scFv/VHH-Fc) significantly boosts expression, likely by avoiding BiP retention during expression/folding.
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
2/ This builds directly on our prior repRNA antibody work showing you can drive potent in vivo expression of mAbs from RNA platforms: www.cell.com/molecular-th...
cell.com
Intramuscular Delivery of Replicon RNA Encoding ZIKV-117 Human Monoclonal Antibody Protects against Zika Virus Infection
Erasmus and Archer et al. describe the optimization of monoclonal antibody expression from replicon RNA in order to enable efficacy following intramuscular delivery of formulated RNA. Using Zika virus...
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Jesse Erasmus @jesseerasmus.bsky.social · 30/04/2026
1/ 🧪 New paper out in @moltherapy.bsky.social: An RNA-to-RNA pipeline for rapid antiviral antibody development. www.cell.com/molecular-th... The goal was to use RNA vaccines to enable antibody discovery in alpacas and then develop those antibodies as RNA-encoded biologics
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Jesse Erasmus @jesseerasmus.bsky.social · 15/12/2025
🧪Published my first commentary on RNA vaccines against nonenveloped viruses. www.cell.com/molecular-th...
cell.com
Replication not required: mRNA vaccines take on non-enveloped viruses
Enterovirus D68 (EV-D68), a respiratory pathogen increasingly associated with acute flaccid myelitis (AFM),1,2,3 represents a growing unmet need for vaccination. Kunishima et al. report an mRNA vaccin...
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Jesse Erasmus @jesseerasmus.bsky.social · 11/11/2025
In my new Nucleic Acid Insights interview, I discuss the evolving science of RNA therapeutics. Addresses safety, manufacturing, and delivery, and how HDT Bio’s LION platform moves beyond LNPs to enable potent, localized, extrahepatic RNA delivery. www.insights.bio/nucleic-acid...
insights.bio
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Gustavo Palacios @guspalpog.bsky.social · 21/10/2025
Excited to announce our new ARPA-H award to “Close the DOORs” mapping how viruses exploit human cells and learning how to shut them. Grateful to @arpa-h.bsky.social and our amazing team! 🔗 www.mountsinai.org/about/newsro... #ARPAH #Virology #HostPathogen #Innovation #Science
mountsinai.org
Mount Sinai Awarded Up to $11.8 Million From ARPA-H to Close the Doors in Human Cells That Viruses Exploit to Infect, Replicate, and Spread
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Matthew Alexander, PhD @mattmuscleguy.bsky.social · 15/10/2025
New #NatureComms paper: Muscle-specific gene editing therapy via mammalian fusogen-directed virus-like particles. #Myoblue tinyurl.com/35wcweap
tinyurl.com
Muscle-specific gene editing therapy via mammalian fusogen-directed virus-like particles - Nature Communications
Genetic muscle diseases are difficult to treat due to challenges in delivering gene editors to muscles throughout the body. Here, authors engineer muscle-specific virus-like particles that fuse with s...
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Jesse Erasmus @jesseerasmus.bsky.social · 09/10/2025
Follow up publication describing immunogenicity and efficacy in NHPs of historical and contemporary H5N1 vaccine compositions against challenge with contemporary cattle virus isolate. What we concluded in mice did not translate to NHPs. www.science.org/doi/10.1126/...
science.org
A replicating RNA vaccine protects cynomolgus macaques against lethal clade 2.3.4.4b influenza A H5N1 virus challenge
LION-delivered replicating RNA vaccines are immunogenic and protect cynomolgus macaques against lethal influenza A (H5N1) virus challenge.
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Jesse Erasmus @jesseerasmus.bsky.social · 01/10/2025
bsky.app/profile/jess...
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Jesse Erasmus @jesseerasmus.bsky.social · 01/10/2025
bsky.app/profile/jess...
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Jesse Erasmus @jesseerasmus.bsky.social · 01/10/2025
Some related posts below. bsky.app/profile/jess...
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Jesse Erasmus @jesseerasmus.bsky.social · 01/10/2025
Happy to announce that we have initiated a phase I clinical trial to evaluate safety and immunogenicity of our LION/repRNA vaccine against #CCHF. This is the culmination of a great partnership with NIAID, UTMB, and our federal sponsors. More to come! www.prnewswire.com/news-release...
prnewswire.com
FDA Greenlights HDT Bio's First-in-Class HDT-321 for the Prevention of Deadly Tick-Borne Disease
/PRNewswire/ -- HDT Bio Corporation, a U.S.-based clinical-stage biotechnology company advancing immune-enhancing solutions for global health, biodefense, and...
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Jesse Erasmus @jesseerasmus.bsky.social · 08/08/2025
Seems heads are already rolling.
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Jesse Erasmus @jesseerasmus.bsky.social · 06/08/2025
Even our project, which directly addressed the tolerability and upper respiratory tract immunity gaps highlighted by RFK Jr, was impacted by this decision. They clearly didn’t review the 22 contracts/grants and the data already generated under taxpayer investment. We are 3 yrs into our program…
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Jesse Erasmus @jesseerasmus.bsky.social · 11/07/2025
Excited to meet the D2R community!
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Jesse Erasmus @jesseerasmus.bsky.social · 02/07/2025
Without safety concern but still higher reactogenicity across the board compared to the licensed comparator. Wish there was a way to improve efficacy while retaining the favorable safety profile of the licensed comparator 🤔
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Jesse Erasmus @jesseerasmus.bsky.social · 01/07/2025
Congrats! Super cool finding. Now I want to put gH-UL116-UL141 into our RNA platform and compare to all the other permutations of structural (and now “nonstructural”) antigen candidates.
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Jesse Erasmus @jesseerasmus.bsky.social · 19/06/2025
🧪 New paper from our team at HDT Bio highlighting that combo repRNA vaccines can lead to excessive innate activation that ultimately inhibits vaccine effectiveness in NHPs. Use of repRNA formulations with restricted biodistribution can alleviate systemic innate response and restore effectiveness.
cell.com
Antigen-dependent interplay of formulation, systemic innate responses, and antibody responses to multi-component replicon RNA vaccination
Lipid nanoparticles (LNPs) are a modular, non-viral nucleic acid delivery system. Here, Eygeris and colleagues report that addition of saponin molecules, such as quillaic acid, to LNP formulations can...
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Jesse Erasmus @jesseerasmus.bsky.social · 19/06/2025
No I haven’t. I’ll check it out!
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Jason McLellan @mclellanlab.bsky.social · 18/06/2025
Our latest preprint is now available doi.org/10.1101/2025...! Led by my postdoc, Luqiang Guo @luqiang.bsky.social, we determined a ~2.4 A resolution structure of the hantavirus glycoprotein tetramer on the surface of VLPs. Also determined structures of dimers of tetramers and Fab-bound tetramers.
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Jesse Erasmus @jesseerasmus.bsky.social · 13/06/2025
I didn’t realize you could filter the posts of who you follow! The paper feed is just what I was looking for.
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Jesse Erasmus @jesseerasmus.bsky.social · 13/06/2025
Shook Nelson Mandela’s hand when I was 10 years old at some kind of gathering in a community park. Just remember him getting off a helicopter and walking through a crowd shaking hands, including mine.
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Jeremy Berg @jeremymberg.bsky.social · 06/06/2025
Outstanding op-ed from Carole LaBonne Universities and the government: Which needs the other more? College-based research labs are the workhorses of national progress and prosperity. wapo.st/3ZR1vFm 1/n
wapo.st
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Jesse Erasmus @jesseerasmus.bsky.social · 21/05/2025
Nothing published on this yet. But we are working on it!
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Jesse Erasmus @jesseerasmus.bsky.social · 06/05/2025
Summary: 1) LION/repRNA (don’t confuse with LNP/mRNA) can indeed confer protection on par with the VSV platform (at least in guinea pigs) after one shot. 2) LION & VSV elicited similar IgG titers but with a unique effector profile. LION induced higher ADCP & ADNP activity but lower ADCD. (2/2)
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Jesse Erasmus @jesseerasmus.bsky.social · 06/05/2025
Collab btwn NIAID (Dr. Andrea Marzi’s lab) and HDT Bio just published! 🧪 Filovirus gold-standard VSV vax platform compared to LION/repRNA (each encoding same antigen seq) for ability to provide single-dose protection in guinea pigs against Sudan virus challenge 🧵(1/2) www.nature.com/articles/s41...
nature.com
Single-dose replicon RNA Sudan virus vaccine uniformly protects female guinea pigs from disease - Nature Communications
Sudan virus (SUDV) outbreaks in Uganda created public health concerns due to a lack of approved vaccines. In this study, the authors develop a repRNA SUDV vaccine and demonstrate full protection of a ...
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Jesse Erasmus @jesseerasmus.bsky.social · 04/05/2025
Mice were protected from death and viremia (panels d and e) in the inactivated vaccine group but not from morbidity (panels b and c), suggesting some nuance in the quality of immune response between authentic and inactivated versions. Lots of potential explanations out there.
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Jesse Erasmus @jesseerasmus.bsky.social · 04/05/2025
In fig 5 of the 🔗 paper, I compared the durability of protective immunity elicited by same doses of the exact same virus/vaccine (non replicating). One was inactivated with formalin (open circles); the other was not (closed circles). Inactivation killed durability. www.nature.com/articles/nm....
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Jesse Erasmus @jesseerasmus.bsky.social · 04/05/2025
I noticed this statement from NIH regarding durability of the inactivated approach. I didn’t see any durability data in the published studies of this candidate. Anyone aware of durability studies performed using inactivated virus platforms? I did one experiment in grad school (in thread below).
STAT did receive a comment —
"attributable to the NIH" - that offered a defense of the funding decision. It signaled, however, a lack of clarity about what the project is aiming to achieve, saying vaccines made ising the platform "could provide broad, long-lasting protection against all influenza viral pathogens, including influenza and coronaviruses, with the added potential to block transmission and stop outbreaks at the source." Coronaviruses are not "influenza viral pathogens."
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Jesse Erasmus @jesseerasmus.bsky.social · 01/05/2025
Don’t get me wrong, I’m appalled by what this administration is doing to science. But I think there is something else going on here. Whatever happened will undoubtedly get politicized though.
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Jesse Erasmus @jesseerasmus.bsky.social · 15/04/2025
Just published! Here we report immunogenicity and efficacy of our replicon RNA vaccine against Crimean-Congo hemorrhagic fever in a cynomolgus macaque model of #CCHFV infection. Stay tuned as we advance this candidate in clinical trials. www.thelancet.com/journals/ebi...
thelancet.com
A replicating RNA vaccine confers protection against Crimean-Congo hemorrhagic fever in cynomolgus macaques
Our data demonstrate that our repNP vaccine and NP-specific antibody can protect against CCHFV in non-human primates.
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Kelton Minor @keltonminor.bsky.social · 18/03/2025
There are days in life that shake you. I’m shattered 💔 to share that I just found out that the US Government terminated my 2024 NIH Director’s Early Independence Award (~$2 million), threatening my long-promised assistant professor job at Columbia University & academic career... 1/🧵
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Jesse Erasmus @jesseerasmus.bsky.social · 18/03/2025
Could you link to the first one please?🙏
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bioRxivpreprint @biorxivpreprint.bsky.social · 18/03/2025
Proteins are a source of glycans found in preparations of glycoRNA www.biorxiv.org/content/10.1101/202…
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Denis Wirtz @deniswirtz.bsky.social · 13/03/2025
NIH is the best investment there is. www.forbes.com/sites/michae...
forbes.com
NIH Grants Fueled $95 Billion In FY 2024 Economic Activity, Finds New Report
National Institutes of Health grants generated almost $95 billion in economic activity nationwide in FY 2024 according to a new report by United for Medical Research.
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Jesse Erasmus @jesseerasmus.bsky.social · 07/03/2025
Beautiful day to stand up for science!
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Jesse Erasmus @jesseerasmus.bsky.social · 07/03/2025
To those who attack vaccines over rare adverse events (observed in consenting populations) and defend SpaceX after spaceship explosions put populations at risk (without consent): science, whether in medicine or aerospace, relies on observation & iteration to improve safety. We need science!
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Jesse Erasmus @jesseerasmus.bsky.social · 02/03/2025
Vashon island struggling to roll out of bed this morning.
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Mark Peifer (He, him) @peiferlabunc.bsky.social · 21/02/2025
Ok scientists & those who love science 🧪: here is another exhortation. Call Congress TODAY about the freeze on NIH Council Meetings and Study Sections. Emphasize that this means NO new grants are being funded & labs will soon start to shut down and fire employees. Phone numbers are at: 5calls.org
5calls.org
5 Calls
Spend 5 minutes. Make 5 calls. Make your voice heard.
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