Raj Rajnarayanan

Associate Dean of Research and Associate Professor, NYITCOM at Arkansas State University | My Tweets are my own

[Yunlong Richard Cao @yunlong_cao]

Our BA.3.2.2 study is now published in Nature Microbiology!

Counterintuitively, we found that ancestral-strain immune imprinting protects against BA.3.2.2 through IGHV3-53/66 Class 1 antibodies, helping explain why BA.3.2.2 selectively infects children.

https://t.co/M7YKbsA48b

[Raj Rajnarayanan @RajlabN]

Huge loss!

[Ashish K. Jha @ashishkjha]

It is hard to believe that Helen Branswell has passed away. Just heartbreaking.

On January 4, 2020, Helen wrote STAT's first story on a mystery pneumonia outbreak in China. She saw the pandemic coming well before anyone was paying attention.

Helen was a journalist who knew more than most of the experts she interviewed. She understood the science, the history and the politics of every outbreak she covered. She asked the hardest (and best) questions and never let me get away with a vague answer

Experts learned from her. I certainly did

It's hard to imagine a world of pandemics, biological threats and so much more without a Helen Branswell to explain it all.

https://t.co/kAanDgu1me

[WBC24 @WBC24News]

BREAKING: 7.5 magnitude earthquake hits Panama, GlobalQuake estimates.

[Tedros Adhanom Ghebreyesus @DrTedros]

Last Friday, the 2nd of October, the first media reports emerged of a suspected case of pneumonic plague in a laboratory worker at the Irkutsk Antiplague Research Institute in the Russian Federation.

The lab worker died after being hospitalized with severe pneumonia. Initial media reports suggested pneumonic plague following an accidental lab exposure.

@WHO is aware that the Russian government held a meeting on the 2nd of October because they suspected a resident of the Irkutsk oblast had contracted a dangerous infection.

On Saturday, WHO asked the Russian Federation for more information, in accordance with the International Health Regulations.

On Tuesday, the Russian Federation responded, saying that no case of plague had recently been reported in the Irkutsk oblast, and that they had placed about 200 contacts in quarantine.

However, WHO has requested further information on the laboratory tests conducted on the individual who died and the contacts, more detail on what prompted the public health measures, and details about the health status of the contacts.

We have also sought verification of media reports of a second employee with pneumonia of undetermined cause.

WHO has offered technical support related to plague and lab biosafety and biosecurity.

As we don’t yet have the full picture of this event, we are not able to conduct a full risk assessment.

Timely, complete and transparent information sharing under the International Health Regulations is essential to clarify conflicting reports and enable an accurate assessment of potential public health risks.

[Raj Rajnarayanan @RajlabN]

I’d give it a few more days. Not sure yet if it’s modified or OG. The incubation period is still unclear...probably around a week. With so many unknowns, I wouldn’t jump to conclusions just yet.

[Amesh Adalja @AmeshAA]

The evidence this was plague is thin. Pneumonic plague needs close contact to spread, so a 200-person watch list doesn't fit. A lab accident would mean immediate antibiotics (assuming drug susceptibility), which no one has reported. Quoted in The Atlantic: https://t.co/9q0uLTrwnN

[Raj Rajnarayanan @RajlabN]

The second-death headline currently provides no usable evidence about proximity, duration of contact or a transmission chain. Not sure if this is even connected yet (which hospital?). Source: "Russian Media" outlets doesn't add much!

[Daily Mail @DailyMail]

A second person has died of the plague in Russia's Irkutsk region, local media claimed on Tuesday https://t.co/UD5Q0k8jmC 🔗

[Raj Rajnarayanan @RajlabN]

Nicely summed up!

[Dr. Saskia Popescu @SaskiaPopescu]

Reminder folks - we have a lot of unknowns in this situation. Including if it’s plague (which is manageable btw). Hospital exposures reflect someone seeking medical care when they don’t know what they have. Quarantine is often used haphazardly as a term for general response (contact tracing, prophy, etc.). Lab biosafety failures are concerning and require thorough review. (1/2)

[The Nobel Prize @NobelPrize]

BREAKING NEWS
The Royal Swedish Academy of Sciences has decided to award the 2026 #NobelPrize in Physics to Francis Halzen “for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.”

[Bloomberg @business]

The Ebola virus is spreading to new parts of the Democratic Republic of Congo and exhausted health workers can't keep up https://t.co/JFLScAVlLC

[Raj Rajnarayanan @RajlabN]

CLOSELY Watching the #Irkutsk #plague incident. A suspected lab exposure is serious, but this is not a #pandemic #signal based on what is publicly known: contacts are being monitored and reportedly have negative tests and not symptomatic. Hope it remains contained!

[Raj Rajnarayanan @RajlabN]

@envidreamz Latest update - https://t.co/NLhsgxt2ze

[Raj Rajnarayanan @RajlabN]

Tracking #SARSCoV2 #Lineages - Globally | 4/25/2026

Top lineages -#30DayTrends #G30

XFG.1.1 (5.9%)
RF.5 (5.7%)
RE.2.5 (5.3%)👀
SH.1 (3.4%)
RC.5 (3.3%)
XFG.1.1.2 (2.7%)
RC.1 (2.1%)
RV.1 (2.1%)
SA.1.1 (2.1%)

Tracker: https://t.co/hTtII72vBT
1/n

[Narendra Modi @narendramodi]

An unforgettable conversation with Captain Smit, filled with pride and emotions.

[Erik Karlsson @E_A_Karlsson]

#Cambodia has confirmed its sixth human #H5N1 case of 2026: a 49-year-old man in Oddar Meanchey who had contact with sick and dead chickens. He is receiving care. Chickens on the farm also tested positive. #avianflu #influenza #OneHealth

[NYITCOM @NYITCOMDO]

Viswanathan (Vishwa) Rajagopalan, Ph.D., an associate professor of biomedical and anatomical sciences at @nyitcomar, has been awarded a $573,750 grant from the National Institutes of Health (NIH).

Congrats!

https://t.co/dHOrsGByn4

[Raj Rajnarayanan @RajlabN]

"AI can boost learning productivity, but only for those who use the technology intelligently. Students must resist the temptation to reach for an AI-generated answer before thinking things through for themselves"

[The Economist @TheEconomist]

Widespread adoption of AI has fuelled concerns about the impact the technology might be having on learning. Our charts help explain its educational effects https://t.co/5sPxxU4pYw

[Raj Rajnarayanan @RajlabN]

. @DarioAmodei provides a good starting framework for negotiation rather than a complete solution

..Slow down, global coordination, verification mechanisms.. are pipe dreams at best!

Should consider education/training & proper framework for open-weight/open-source solutions

[Dario Amodei @DarioAmodei]

We Must Pace the Frontier: I’ve written a new essay on why the AI industry should slow down, with a three-part plan for doing so.

Anthropic is unilaterally committing to the first of these steps. We’ll provide third-party evaluators with permanent, employee-level access to our systems, so that they can verify adherence to our safety measures, report on incidents, and assess models’ alignment during training.

You can read the full post here: https://t.co/OGyPb7yaYt

[Raj Rajnarayanan @RajlabN]

Thank you, @AnthropicAI!

The report may show that guardrails are working as intended but it may also reveal only a subset of the problem...

What happens when it is outsourced through backchannels, beyond those guardrails and without security-by-design?

#HallucinatedIllusion

[Anthropic @AnthropicAI]

We're publishing our most detailed threat intelligence report to date.

It covers how people tried to misuse Claude—for cyberattacks, influence operations, surveillance, biology, and building weapons—and how we found and stopped them.

We disrupted every operation in the report, and used the lessons from them to strengthen our safeguards. Where appropriate, we also shared what we found with authorities and other AI companies.

These cases are not typical: we’re highlighting some of the most sophisticated misuse we’ve seen. But they’re especially important to discuss, because they show us where AI misuse is headed, where our safeguards work, and where they need to improve.

We’re publishing this report so others can spot the same activity on their own platforms, and so we can give the public a clearer view of how emerging threats develop.

Read the report: https://t.co/0EJUnYEgfz

[Yunlong Richard Cao @yunlong_cao]

SARS-CoV-2 saltation variant PJ.2.1 has raised concerns over another JN.1-like event.
Here we found:
1. PJ.2.1 shows markedly higher ACE2 binding.
2. PJ.2.1's antigenicity remains comparable to the JN.1 family.
3. No increased immune evasion against human plasma.

While PJ.2.1 currently lacks the immune evasion capabilities of other contemporary strains (XFG, PQ.16.1.1, BA.3.2.2...), its robust baseline receptor-binding strength mirrors the early evolutionary trajectory of BA.2.86 to JN.1, necessitating continued genomic, epidemiological, and virological surveillance of the PJ.2.1 lineage.

Details can be found in the recent BioRxiv manuscript:
https://t.co/r1MmiGGI4u

[Raj Rajnarayanan @RajlabN]

Not one of these trials has published results split by calendar year. Pre-pandemic vs pandemic vs after. It's one graph. It exists in every dataset.

We should start asking to see the data!

5/n

[Raj Rajnarayanan @RajlabN]

15 wins, 11 losses across five years of #cardiovascular outcomes trials (#CVOT). The ratio isn't the story. Which ones failed is

1/n

[Raj Rajnarayanan @RajlabN]

One more thing on the losses: nearly all of them were measured during and after the pandemic. That can't explain a failure. Randomization splits COVID evenly across both arms but it adds noise a drug was never built to overcome.

4/n