I just heard about this:

There’s a travel scam warning going around the internet right now: You should keep your baggage tags on your bags until you get home, then shred them, because scammers are using luggage tags to file fraudulent claims for missing baggage with the airline.

First, the scam is possible. I had a bag destroyed by baggage handlers on a recent flight, and all the information I needed to file a claim was on my luggage tag. I have no idea if I will successfully get any money from the airline, or what form it will be in, or how it will be tied to my name, but at least the first step is possible...

In an unhappy coincidence, the Covid-19 pandemic and Angie Jo’s doctoral studies in political science both began in 2019. Paradoxically, this global catastrophe helped define her primary research thrust.

As countries reacted with unprecedented fiscal measures to protect their citizens from economic collapse, Jo MCP ’19 discerned striking patterns among these interventions: Nations typically seen as the least generous on social welfare were suddenly deploying the most dramatic emergency responses.

“I wanted to understand why countries like the U.S., which famously offer minimal state support, suddenly mobilize an enormous emergency response to a crisis — only to let it vanish after the crisis passes,” says Jo.

Driven by this interest, Jo launched into a comparative exploration of welfare states that forms the backbone of her doctoral research. Her work examines how different types of welfare regimes respond to collective crises, and whether these responses lead to lasting institutional reforms or merely temporary patches.

A mismatch in investments

Jo’s research focuses on a particular subset of advanced industrialized democracies — countries like the United States, United Kingdom, Canada, and Australia — that political economists classify as “liberal welfare regimes.” These nations stand in contrast to the “social democratic welfare regimes” exemplified by Scandinavian countries.

“In everyday times, citizens in countries like Denmark or Sweden are already well-protected by a deep and comprehensive welfare state,” Jo explains. “When something like Covid hits, these countries were largely able to use the social policy tools and administrative infrastructure they already had, such as subsidized childcare and short-time work schemes that prevent mass layoffs.”

Liberal welfare regimes, however, exhibit a different pattern. During normal periods, "government assistance is viewed by many as the last resort,” Jo observes. “It’s means-tested and minimal, and the responsibility to manage risk is put on the individual.”

Yet when Covid struck, these same governments “spent historically unprecedented amounts on emergency aid to citizens, including stimulus checks, expanded unemployment insurance, child tax credits, grants, and debt forbearance that might normally have faced backlash from many Americans as government ‘handouts.’”

This stark contrast — minimal investment in social safety nets during normal times followed by massive crisis spending — lies at the heart of Jo’s inquiry. “What struck me was the mismatch: The U.S. invests so little in social welfare at baseline, but when crisis hits, it can suddenly unleash massive aid — just not in ways that stick. So what happens when the next crisis comes?”

From architecture to political economy

Jo took a winding path to studying welfare states in crisis. Born in South Korea, she moved with her family to California at age 3 as her parents sought an American education for their children. After moving back to Korea for high school, she attended Harvard University, where she initially focused on art and architecture.

“I thought I’d be an artist,” Jo recalls, “but I always had many interests, and I was very aware of different countries and different political systems, because we were moving around a lot.”

While studying architecture at Harvard, Jo’s academic focus pivoted.

“I realized that most of the decisions around how things get built, whether it’s a building or a city or infrastructure, are made by the government or by powerful private actors,” she explains. “The architect is the artist’s hand that is commissioned to execute, but the decisions behind it, I realized, were what interested me more.”

After a year working in macroeconomics research at a hedge fund, Jo found herself drawn to questions in political economy. “While I didn’t find the zero-sum game of finance compelling, I really wanted to understand the interactions between markets and governments that lay behind the trades,” she says.

Jo decided to pursue a master’s degree in city planning at MIT, where she studied the political economy of master-planning new cities as a form of industrial policy in China and South Korea, before transitioning to the political science PhD program. Her research focus shifted dramatically when the Covid-19 pandemic struck.

“It was the first time I realized, wow, these wealthy Western democracies have serious problems, too,” Jo says. “They are not dealing well with this pandemic and the structural inequalities and the deep tensions that have always been part of some of these societies, but are being tested even further by the enormity of this shock.”

The costs of crisis response

One of Jo’s key insights challenges conventional wisdom about fiscal conservatism. The assumption that keeping government small saves money in the long run may be fundamentally flawed when considering crisis response.

“What I’m exploring in my research is the irony that the less you invest in a capable, effective and well-resourced government, the more that backfires when a crisis inevitably hits and you have to patch up the holes,” Jo argues. “You’re not saving money; you’re deferring the cost.”

This inefficiency becomes particularly apparent when examining how different countries deployed aid during Covid. Countries like Denmark, with robust data systems connecting health records, employment information, and family data, could target assistance with precision. The United States, by contrast, relied on blunter instruments.

“If your system isn’t built to deliver aid in normal times, it won’t suddenly work well under pressure,” Jo explains. “The U.S. had to invent entire programs from scratch overnight — and many were clumsy, inefficient, or regressive.”

There is also a political aspect to this constraint. “Not only do liberal welfare countries lack the infrastructure to address crises, they are often governed by powerful constituencies that do not want to build it — they deliberately choose to enact temporary benefits that are precisely designed to fade,” Jo argues. “This perpetuates a cycle where short-term compensations are employed from crisis to crisis, constraining the permanent expansion of the welfare state.”

Missed opportunities

Jo’s dissertation also examines whether crises provide opportunities for institutional reform. Her second paper focuses on the 2008 financial crisis in the United States, and the Hardest Hit Fund, a program that allocated federal money to state housing finance agencies to prevent foreclosures.

“I ask why, with hundreds of millions in federal aid and few strings attached, state agencies ultimately helped so few underwater homeowners shed unmanageable debt burdens,” Jo says. “The money and the mandate were there — the transformative capacity wasn’t.”

Some states used the funds to pursue ambitious policy interventions, such as restructuring mortgage debt to permanently reduce homeowners’ principal and interest burdens. However, most opted for temporary solutions like helping borrowers make up missed payments, while preserving their original contract. Partisan politics, financial interests, and status quo bias are most likely responsible for these varying state strategies, Jo believes.

She sees this as “another case of the choice that governments have between throwing money at the problem as a temporary Band-Aid solution, or using a crisis as an opportunity to pursue more ambitious, deeper reforms that help people more sustainably in the long run.”

The significance of crisis response research

For Jo, understanding how welfare states respond to crises is not just an academic exercise, but a matter of profound human consequence.

“When there’s an event like the financial crisis or Covid, the scale of suffering and the welfare gap that emerges is devastating,” Jo emphasizes. “I believe political science should be actively studying these rare episodes, rather than disregarding them as once-in-a-century anomalies.”

Her research carries implications for how we think about welfare state design and crisis preparedness. As Jo notes, the most vulnerable members of society — “people who are unbanked, undocumented, people who have low or no tax liability because they don’t make enough, immigrants or those who don’t speak English or don’t have access to the internet or are unhoused” — are often invisible to relief systems.

As Jo prepares for her career in academia, she is motivated to apply her political science training to address such failures. “We’re going to have more crises, whether pandemics, AI, climate disasters, or financial shocks,” Jo warns. “Finding better ways to cover those people is essential, and is not something that our current welfare state — or our politics — are designed to handle.”

Every year, global health experts are faced with a high-stakes decision: Which influenza strains should go into the next seasonal vaccine? The choice must be made months in advance, long before flu season even begins, and it can often feel like a race against the clock. If the selected strains match those that circulate, the vaccine will likely be highly effective. But if the prediction is off, protection can drop significantly, leading to (potentially preventable) illness and strain on health care systems.

This challenge became even more familiar to scientists in the years during the Covid-19 pandemic. Think back to the time (and time and time again), when new variants emerged just as vaccines were being rolled out. Influenza behaves like a similar, rowdy cousin, mutating constantly and unpredictably. That makes it hard to stay ahead, and therefore harder to design vaccines that remain protective.

To reduce this uncertainty, scientists at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and the MIT Abdul Latif Jameel Clinic for Machine Learning in Health set out to make vaccine selection more accurate and less reliant on guesswork. They created an AI system called VaxSeer, designed to predict dominant flu strains and identify the most protective vaccine candidates, months ahead of time. The tool uses deep learning models trained on decades of viral sequences and lab test results to simulate how the flu virus might evolve and how the vaccines will respond.

Traditional evolution models often analyze the effect of single amino acid mutations independently. “VaxSeer adopts a large protein language model to learn the relationship between dominance and the combinatorial effects of mutations,” explains Wenxian Shi, a PhD student in MIT’s Department of Electrical Engineering and Computer Science, researcher at CSAIL, and lead author of a new paper on the work. “Unlike existing protein language models that assume a static distribution of viral variants, we model dynamic dominance shifts, making it better suited for rapidly evolving viruses like influenza.”

An open-access report on the study was published today in Nature Medicine.

The future of flu

VaxSeer has two core prediction engines: one that estimates how likely each viral strain is to spread (dominance), and another that estimates how effectively a vaccine will neutralize that strain (antigenicity). Together, they produce a predicted coverage score: a forward-looking measure of how well a given vaccine is likely to perform against future viruses.

The scale of the score could be from an infinite negative to 0. The closer the score to 0, the better the antigenic match of vaccine strains to the circulating viruses. (You can imagine it as the negative of some kind of “distance.”)

In a 10-year retrospective study, the researchers evaluated VaxSeer’s recommendations against those made by the World Health Organization (WHO) for two major flu subtypes: A/H3N2 and A/H1N1. For A/H3N2, VaxSeer’s choices outperformed the WHO’s in nine out of 10 seasons, based on retrospective empirical coverage scores (a surrogate metric of the vaccine effectiveness, calculated from the observed dominance from past seasons and experimental HI test results). The team used this to evaluate vaccine selections, as the effectiveness is only available for vaccines actually given to the population. 

For A/H1N1, it outperformed or matched the WHO in six out of 10 seasons. In one notable case, for the 2016 flu season, VaxSeer identified a strain that wasn’t chosen by the WHO until the following year. The model’s predictions also showed strong correlation with real-world vaccine effectiveness estimates, as reported by the CDC, Canada’s Sentinel Practitioner Surveillance Network, and Europe’s I-MOVE program. VaxSeer’s predicted coverage scores aligned closely with public health data on flu-related illnesses and medical visits prevented by vaccination.

So how exactly does VaxSeer make sense of all these data? Intuitively, the model first estimates how rapidly a viral strain spreads over time using a protein language model, and then determines its dominance by accounting for competition among different strains.

Once the model has calculated its insights, they’re plugged into a mathematical framework based on something called ordinary differential equations to simulate viral spread over time. For antigenicity, the system estimates how well a given vaccine strain will perform in a common lab test called the hemagglutination inhibition assay. This measures how effectively antibodies can inhibit the virus from binding to human red blood cells, which is a widely used proxy for antigenic match/antigenicity. 

Outpacing evolution

“By modeling how viruses evolve and how vaccines interact with them, AI tools like VaxSeer could help health officials make better, faster decisions — and stay one step ahead in the race between infection and immunity,” says Shi. 

VaxSeer currently focuses only on the flu virus’s HA (hemagglutinin) protein,the major antigen of influenza. Future versions could incorporate other proteins like NA (neuraminidase), and factors like immune history, manufacturing constraints, or dosage levels. Applying the system to other viruses would also require large, high-quality datasets that track both viral evolution and immune responses — data that aren’t always publicly available. The team, however is currently working on the methods that can predict viral evolution in low-data regimes building on relations between viral families

“Given the speed of viral evolution, current therapeutic development often lags behind. VaxSeer is our attempt to catch up,” says Regina Barzilay, the School of Engineering Distinguished Professor for AI and Health at MIT, AI lead of Jameel Clinic, and CSAIL principal investigator. 

“This paper is impressive, but what excites me perhaps even more is the team’s ongoing work on predicting viral evolution in low-data settings,” says Assistant Professor Jon Stokes of the Department of Biochemistry and Biomedical Sciences at McMaster University in Hamilton, Ontario. “The implications go far beyond influenza. Imagine being able to anticipate how antibiotic-resistant bacteria or drug-resistant cancers might evolve, both of which can adapt rapidly. This kind of predictive modeling opens up a powerful new way of thinking about how diseases change, giving us the opportunity to stay one step ahead and design clinical interventions before escape becomes a major problem.”

Shi and Barzilay wrote the paper with MIT CSAIL postdoc Jeremy Wohlwend ’16, MEng ’17, PhD ’25 and recent CSAIL affiliate Menghua Wu ’19, MEng ’20, PhD ’25. Their work was supported, in part, by the U.S. Defense Threat Reduction Agency and MIT Jameel Clinic.

Today’s electric vehicle boom is tomorrow’s mountain of electronic waste. And while myriad efforts are underway to improve battery recycling, many EV batteries still end up in landfills.

A research team from MIT wants to help change that with a new kind of self-assembling battery material that quickly breaks apart when submerged in a simple organic liquid. In a new paper published in Nature Chemistry, the researchers showed the material can work as the electrolyte in a functioning, solid-state battery cell and then revert back to its original molecular components in minutes.

The approach offers an alternative to shredding the battery into a mixed, hard-to-recycle mass. Instead, because the electrolyte serves as the battery’s connecting layer, when the new material returns to its original molecular form, the entire battery disassembles to accelerate the recycling process.

“So far in the battery industry, we’ve focused on high-performing materials and designs, and only later tried to figure out how to recycle batteries made with complex structures and hard-to-recycle materials,” says the paper’s first author Yukio Cho PhD ’23. “Our approach is to start with easily recyclable materials and figure out how to make them battery-compatible. Designing batteries for recyclability from the beginning is a new approach.”

Joining Cho on the paper are PhD candidate Cole Fincher, Ty Christoff-Tempesta PhD ’22, Kyocera Professor of Ceramics Yet-Ming Chiang, Visiting Associate Professor Julia Ortony, Xiaobing Zuo, and Guillaume Lamour.

Better batteries

There’s a scene in one of the “Harry Potter” films where Professor Dumbledore cleans a dilapidated home with the flick of the wrist and a spell. Cho says that image stuck with him as a kid. (What better way to clean your room?) When he saw a talk by Ortony on engineering molecules so that they could assemble into complex structures and then revert back to their original form, he wondered if it could be used to make battery recycling work like magic.

That would be a paradigm shift for the battery industry. Today, batteries require harsh chemicals, high heat, and complex processing to recycle. There are three main parts of a battery: the positively charged cathode, the negatively charged electrode, and the electrolyte that shuttles lithium ions between them. The electrolytes in most lithium-ion batteries are highly flammable and degrade over time into toxic byproducts that require specialized handling.

To simplify the recycling process, the researchers decided to make a more sustainable electrolyte. For that, they turned to a class of molecules that self-assemble in water, named aramid amphiphiles (AAs), whose chemical structures and stability mimic that of Kevlar. The researchers further designed the AAs to contain polyethylene glycol (PEG), which can conduct lithium ions, on one end of each molecule. When the molecules are exposed to water, they spontaneously form nanoribbons with ion-conducting PEG surfaces and bases that imitate the robustness of Kevlar through tight hydrogen bonding. The result is a mechanically stable nanoribbon structure that conducts ions across its surface.

“The material is composed of two parts,” Cho explains. “The first part is this flexible chain that gives us a nest, or host, for lithium ions to jump around. The second part is this strong organic material component that is used in the Kevlar, which is a bulletproof material. Those make the whole structure stable.”

When added to water, the nanoribbons self-assemble to form millions of nanoribbons that can be hot-pressed into a solid-state material.

“Within five minutes of being added to water, the solution becomes gel-like, indicating there are so many nanofibers formed in the liquid that they start to entangle each other,” Cho says. “What’s exciting is we can make this material at scale because of the self-assembly behavior.”

The team tested the material’s strength and toughness, finding it could endure the stresses associated with making and running the battery. They also constructed a solid-state battery cell that used lithium iron phosphate for the cathode and lithium titanium oxide as the anode, both common materials in today’s batteries. The nanoribbons moved lithium ions successfully between the electrodes, but a side-effect known as polarization limited the movement of lithium ions into the battery’s electrodes during fast bouts of charging and discharging, hampering its performance compared to today’s gold-standard commercial batteries.

“The lithium ions moved along the nanofiber all right, but getting the lithium ion from the nanofibers to the metal oxide seems to be the most sluggish point of the process,” Cho says.

When they immersed the battery cell into organic solvents, the material immediately dissolved, with each part of the battery falling away for easier recycling. Cho compared the materials’ reaction to cotton candy being submerged in water.

“The electrolyte holds the two battery electrodes together and provides the lithium-ion pathways,” Cho says. “So, when you want to recycle the battery, the entire electrolyte layer can fall off naturally and you can recycle the electrodes separately.”

Validating a new approach

Cho says the material is a proof of concept that demonstrates the recycle-first approach.

“We don’t want to say we solved all the problems with this material,” Cho says. “Our battery performance was not fantastic because we used only this material as the entire electrolyte for the paper, but what we’re picturing is using this material as one layer in the battery electrolyte. It doesn’t have to be the entire electrolyte to kick off the recycling process.”

Cho also sees a lot of room for optimizing the material’s performance with further experiments.

Now, the researchers are exploring ways to integrate these kinds of materials into existing battery designs as well as implementing the ideas into new battery chemistries.

“It’s very challenging to convince existing vendors to do something very differently,” Cho says. “But with new battery materials that may come out in five or 10 years, it could be easier to integrate this into new designs in the beginning.”

Cho also believes the approach could help reshore lithium supplies by reusing materials from batteries that are already in the U.S.

“People are starting to realize how important this is,” Cho says. “If we can start to recycle lithium-ion batteries from battery waste at scale, it’ll have the same effect as opening lithium mines in the U.S. Also, each battery requires a certain amount of lithium, so extrapolating out the growth of electric vehicles, we need to reuse this material to avoid massive lithium price spikes.”

The work was supported, in part, by the National Science Foundation and the U.S. Department of Energy.