U.S. politicians have perhaps never been more divided, including when it comes to their views on higher education.

Republicans are pushing for more control over the day-to-day work at colleges and universities. Some Republican politicians say that universities are elitist, woke organizations that are out of touch with the general public and lack value for most people. In step with this rhetoric, they have cut funding to higher education, including slashing grants to universities with ethnically and racially diverse student bodies.

Democrats, meanwhile, broadly support higher education, praising it for its role in improving people’s lives. They are challenging these cuts and the Trump administration’s mounting interference into how colleges are run.

Despite these differences, both Democrats and Republicans invest billions in higher education and issue billions annually in federal earmarks. Federal earmarks are taxpayer-funded spending provisions that Congress members allocate, with minimal oversight, to projects or organizations that typically align with their priorities.

For fiscal year 2026, spanning October 2025 through September 2026, Congress allocated US$16 billion in earmarks to a range of causes – approximately $2 billion of which went to colleges and universities across the country.

We are scholars of higher education who have analyzed federal earmarking patterns in recent years. Our May 2026 study considers how party affiliation shapes universities’ earmark outcomes.

Where do Republicans and Democrats funnel academic earmarks? Does either party put this money where their mouth is? The data tells a story of partisan preferences that are predictable in some ways and surprising in others.

Understanding federal earmarks

Some critics call federal earmarks “congressional pork” and describe them as wasteful pet projects used to curry political favor.

However, Congress has long leveraged earmarks to fund expensive and important infrastructural projects, like airport updates. Earmarks can also help colleges pay for expensive construction projects they might not be able to otherwise afford, especially as college enrollment declines and state and local funding to higher education decreases.

Current federal guidelines cap federal earmarks to 1% of total federal discretionary spending. Currently, each member of Congress may issue 15 earmark requests to the House Committee on Appropriations each fiscal year.

The House and Senate appropriations committees ultimately negotiate and decide which projects receive funding, and how much.

Not all schools receive the same

Our 2024 study showed that Congress, as a whole, earmarked far less funding to minority-serving institutions and community colleges compared with what it gave to well-endowed research universities.

Minority-serving institutions,like historically Black colleges and universities and tribal colleges and universities, serve large shares of students of color and low-income students. They are generally underfunded.

Recent reports indicate that Congress members may also favor their alma maters when doling out earmarks.

Twenty-four senators – 13 Democrats and 11 Republicans – collectively requested approximately $636 million for projects at their alma maters in fiscal year 2026. But Republicans were responsible for nearly three-fourths of those requests, or $470 million.

For example, Senator Jim Justice, a Republican from West Virginia, requested nearly $60 million across seven earmark projects for his alma mater, Marshall University.

Republicans’ earmark tendencies

Contrary to their largely fiscal conservative rhetoric and critiques of universities as overly woke and elitist, Republicans generally sponsor earmarks with gusto across the board, including for colleges and universities.

Eight Republicans were among the 10 most generous earmark sponsors in fiscal year 2026. Republicans also made up 27 of the 31 representatives who requested $50 million or more from that year’s budget.

Based on our analysis, from October 2021 through September 2023, Republicans sponsored $230 million more in earmarks to colleges and universities than their Democratic colleagues did.

Republicans also tended to send less in earmarked funding to colleges and universities serving large numbers of students who receive need-based federal financial aid, per our findings. Rather, Republicans were more likely to earmark money for whiter, wealthier universities, like the University of North Carolina, Chapel Hill or the University of Michigan.

For example, Senator Mitch McConnell directed just shy of $60 million in earmarks to two large research universities, University of Louisville and the University of Kentucky, for fiscal year 2026. McConnell attended both of those schools.

Nearly 70% and just over 75% of the undergraduates at the University of Louisville and the University of Kentucky, respectively, identify as white.

That same year, McConnell sponsored a $2 million earmark project for a single community college in the state – Madisonville Community College.

He did not sponsor any earmarks for the state’s two historically Black colleges and universities: Simmons University and Kentucky State University.

Democrats’ earmark tendencies

Democrats, meanwhile, generally walk the talk in terms of which colleges and universities they fund, generally supporting minority-serving institutions and campuses with large numbers of students who receive Pell Grants. Pell Grants are a form of federal financial aid for low-income students that they do not have to repay, unlike loans.

Our analysis specifically shows Democrats gave these schools an outsized share of the pot of earmarked dollars, relative to what they gave overall to colleges and universities.

Some Democrats also sponsored earmarks to minority-serving institutions beyond their own districts.

For example, while Florida International University is in Republican Representative Mario Diaz-Balart’s district, he did not request earmark funding be sent their way in 2022. Rather, that year, Representative Debbie Wasserman Schultz, a Democrat from another district in Florida, secured a $2 million earmark for the university to support its public health and social work programming.

However, Democrats’ earmarks are much smaller than their Republican counterparts and generally far too small to level the playing field for minority-serving institutions, which are chronically underfunded.

So, while Democrats direct more earmarks to minority-serving institutions than Republicans, the comparatively small size of those awards cannot close the funding gap these schools face.

In 2026, for example, the Democratic senators from California, Alex Padilla and Adam Schiff, secured a $3.5 million earmark to support the University of California, Merced’s medical school. This is a Hispanic-serving institution, meaning a college or university where at least 25% of undergraduates are Hispanic.

At the same time, Republican Senator John Boozman from Arkansas secured $45 million in earmarks to upgrade the University of Arkansas Medical Center, which is a predominantly white school.

Based on our research, it seems that both parties have real, if different, work to do to fully leverage earmarks to support higher education.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

At a time when hard-fought primary elections in Georgia, Kentucky and Indiana and Ohio are making national news, perennial battleground Pennsylvania seems to be nodding through one of the sleepiest primary seasons in a long time.

I’m an associate professor of political science at the University of Pittsburgh. My research focuses on how political institutions like political parties and state and local governments affect political representation.

In statewide races, only the Republican lieutenant governor slot is contested, a race between GOP-endorsed attorney Jason Richey and newcomer John Ventre. In the state Senate, less than a third of incumbents drew a challenger. Only 21 of the 203 state Assembly seats see an incumbent facing an in-party challenge. So why does Pennsylvania, usually a hotbed of political strife, appear to be sitting this midterm primary season out?

Uncontested primaries are normal

According to political scientists Shigeo Hirano and James M. Snyder Jr., uncontested primaries, and uncontested elections in general, are normal – and can even be a good thing. They argue it’s because high quality candidates do not tend to draw a challenge. This means that an uncontested primary signifies the district has no potential candidates who both want the job and think they can win against the incumbent.

The biggest reason challengers stay home is because of a well-dug-in incumbent, and Pennsylvania had plenty of those this cycle. Unlike in Indiana, no wave of anti-establishment energy is giving long-shot challengers a fighting chance.

Interestingly, the moderate Trump foe and incumbent Brian Fitzpatrick, a Republican state representative from Bucks County, managed to avoid a primary challenge this year. Fitzpatrick was one of only two Republicans to vote against the H.R. 1 Act – also known as President Donald J. Trump’s “One Big Beautiful Bill.”

The only other dissenting vote came from Kentucky’s Thomas Massie — and the President responded by personally recruiting a primary challenger to run against him.

Why Pennsylvania’s Fitzpatrick got a pass

So how did Fitzpatrick manage to avoid Trump’s notice? It helps to compare his political fortunes with Massie’s.

Massie’s district is solidly red. He typically wins at least 60% of his general election vote. In 2024, no Democrat even ran against him.

Fitzpatrick, on the other hand, hails from a decidedly “purple” district where the vote could go in either party’s direction. He rarely wins more than 55% of the vote, and is perennially on the list of the most at-risk Republican incumbents.

In other words, in a midterm election in which Republicans face strong competition and fear losing the House of Representatives, Republicans need Fitzpatrick more than they need Massie. Without Fitzpatrick, his district is much more likely to fall in the Democratic column. Without Massie, Republicans can still expect to keep the seat red.

Pennsylvania parties hold the key

Pennsylvania incumbents have mostly been able to avoid finding themselves part of a larger conflict.

Some of the most contested primaries this election cycle stem from disputes centered on President Trump’s push for Republican-led states to redraw their congressional district lines. But the Commonwealth of Pennsylvania, with its closely divided state legislature, is not going to change its electoral map anytime soon. So the Commonwealth was left out of partisan gerrymandering disputes.

Pennsylvania remains one of only 13 American states that holds closed primary elections. That means voters must already be registered as party members to vote in that party’s primary. In an open, or even semi-open, primary state like Michigan and Iowa, potential challengers can try to win a primary election by relying on new voters choosing to align with the party only for that election day, or even for that specific election.

A closed party system gives party regulars, and the party organization itself, enormous sway over who gets nominated. Potential candidates in closed-party states are much better off working within the party organization and waiting for an incumbent to step down before throwing their hats in the ring.

Pennsylvania is a closed-party state and a swing state. In an election cycle in which political parties from West Virginia’s Republicans to California’s Democrats seem to be turning on their own members, Democrats and Republicans in the Commonwealth of Pennsylvania have managed to keep their parties more unified.

The desire for party fealty is strong, but not as strong as the need to win in the general election. Pennsylvania parties are powerful, and they are staying cautious until November. An uncontested primary, in other words, isn’t a sign of apathy. In Pennsylvania, it’s strategy.

Kristin Kanthak does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

For millions of people, cannabis has become the unofficial prescription for lost sleep. But what feels like a solution may be quietly making the problem worse.

Consider these two cases:

She is 15 and has been lying in bed for the past hour. It is past midnight, and her brain will not quiet down. Her school bus comes at 6:20 a.m. She is getting anxious, knowing that she needs to wake up in six hours. She did all the right things: turned off her phone at 10 p.m., tried melatonin. So tonight she tries something a friend recommended: a cannabis gummy. Within 20 minutes, she’s asleep.

He is 34, a veteran who did two tours and has struggled with sleep since coming home. It takes him two hours to fall asleep, and when he does, he is jolted awake by relentless nightmares. He hasn’t slept more than three hours a night in months, and it’s catching up with him. His buddy swears that cannabis helped him, and with a six-month waiting list for a sleep consultation at the Veteran’s Affairs medical center and a cannabis dispensary six blocks away that’s open until 10 p.m., the decision doesn’t feel complicated.

Both will tell you cannabis works for their specific needs. They are not entirely wrong. But no one has told them what is actually happening inside the brain when the lights go out. It’s complex, and for them – as for many others – ultimately it’s a trap.

As a neurologist specializing in sleep and brain performance, I write this not as someone opposed to cannabis but as someone who regularly sees patients whose sleep has quietly unraveled after months or years of use, especially teenagers and veterans.

I believe the public deserves a more complete picture than they currently have due to the limited research that’s available.

Why the teenage brain is especially vulnerable

From the early teens through the mid-20s, the brain is actively under construction, clearing out weak or redundant connections and reinforcing the circuits responsible for judgment, emotional regulation and stress response.

Tetrahydrocannabinol, or THC, the psychoactive component of cannabis, interferes with this process directly by acting on the endocannabinoid system, one of the primary regulatory networks guiding it.

A 2021 brain imaging study of 799 teenagers found that cannabis use was associated with dose-dependent thinning of the cerebral cortex – meaning the more cannabis a teenager used, the thinner their prefrontal cortex became. The prefrontal cortex is the region of the brain responsible for judgment, decision-making and impulse control. Thinning of the cortex in this region has been associated with increased impulsivity, poorer decision-making and reduced inhibitory control.

Another seldom-discussed factor is how puberty affects sleep. Hormonal changes and brain maturation in adolescence shift the internal biological clock, known as the circadian rhythm, toward a later sleep schedule.

And teenagers are far from alone. A 2025 study found that more than 1 in 5 young adults in the U.S. turn to cannabis or alcohol to fall asleep. For teenagers who are already sleep-deprived and facing early school start times, cannabis can become its own nightly fix.

What cannabis is doing while you sleep

Sleep is not passive. It is well-organized, purposeful and foundational to our physical and brain health.

Every night, the brain cycles through distinct stages, each serving a specific function. All sleep stages matter, but the one that matters most is REM sleep, the dreaming stage. This is when the brain processes the emotional weight of the day, locks in learning and resets the brain circuits that govern mood, judgment and resilience.

THC has a sedative effect at low doses but is stimulating at high doses. Cannabis also contains other cannabinoids – plant-derived compounds such as CBD and CBN that interact with a system in the body that produces its own cannabinoids and contributes to the sedative effects of cannabis.

Here is where it gets complicated.

THC does help people fall asleep faster, but that effect fades quickly as the body adapts to regular use. The same gummy that once helped someone fall asleep quickly does less. They need more to get the same effect.

In addition, falling asleep quicker is not the same as sleeping well. A 2025 review of the research to date found that cannabis does not consistently improve sleep overall, including how long people stay asleep or how restful that sleep is.

In a separate study, chronic daily users spent significantly more time awake during the night and got less restful sleep compared with nonusers; another study found that using cannabis close to bedtime had similar effects.

In other words, the subjective sense of sleeping better does not match what the brain recordings show.

When relief becomes reliance

At this point many people are using cannabis not because it is working well, but because stopping feels worse.

Even when chronic cannabis users have the willpower to stop, they often face brutal withdrawal symptoms that are more severe than what drove them to cannabis in the first place. Sleep disturbance, including insomnia and disturbing dreams, is described as a common manifestation of cannabis withdrawal. In addition, two-thirds of users report other symptoms such as anxiety, depressed mood, restlessness, irritability, decreased appetite or a combination of these symptoms that often persist for weeks after stopping use.

The discomfort of withdrawal drives many people to keep using it.

This is the trap – it’s quiet and insidious, which makes it harder to see.

Cannabis works just enough to feel like a solution. Night after night it dulls the problem without fixing it, until stopping feels unthinkable. When someone finally tries to quit, their sleep falls apart. So they go back. The original reason they could not sleep has not been identified or treated, and it hasn’t gone away.

Veterans and the need for long-term recovery

The developing brain is one kind of vulnerability. The traumatized brain is another.

Post-traumatic stress disorder affects an estimated 12% to 23% of post-9/11 veterans, compared with 6% to 8% of the general population. Sleep disturbances affect 70% to 90% of military personnel with PTSD. People with PTSD commonly have nightmares that are visceral, relentless and exhausting. They might be jolted awake with a pounding heart, multiple times a night, for years.

As a result, many veterans turn to cannabis to help them sleep. It’s understandable, especially when it can take weeks or months to get an appointment with a mental health practitioner.

But the data on outcomes for veterans is sobering. Those with cannabis use disorder – meaning cannabis use they struggle to control despite negative consequences, which affects roughly 1 in 4 veterans who use cannabis nonmedically – have higher rates of depression, anxiety and suicidal ideation and respond much more poorly to evidence-based PTSD treatments.
And then there is withdrawal. When a veteran tries to stop, the same symptoms that cannabis seemed to quiet come roaring back in potentially dangerous ways – rebound insomnia and nightmares, worsening depression and, in some cases, thoughts of suicide.

Because these withdrawal symptoms so closely mirror PTSD itself, many veterans interpret the return of symptoms as their condition worsening, not as withdrawal, so they go back to cannabis. And the cycle continues.

What actually works, and why it’s so hard to get

Cognitive behavioral therapy for insomnia, or CBT-I, is considered the first-line treatment for persistent insomnia. Research shows that it outperforms every sleep medication, cannabis included.

This therapy works by modifying sleep habits, regulating sleep-wake schedules, reducing arousal and reframing unhelpful beliefs about sleep. A form of treatment known as image rehearsal therapy, in which patients rewrite the storyline of a recurring nightmare and mentally rehearse the new version while awake, has been shown to be effective for veterans with trauma-related nightmares. But trained CBT-I providers are scarce, wait times are long, and most primary care settings do not offer it.

In other words, the people most vulnerable to the sleep-related harms of cannabis use are the least likely to have access to treatments that address the underlying problem, and the most likely to get caught in a negative cycle.

For those already caught in that cycle, quitting abruptly rarely works and often makes things worse. Research shows that CBT-I can reduce both insomnia and cannabis use at the same time – treating the root problem so cannabis no longer feels necessary.

Sleep is the foundation on which memory, mood, judgment and recovery are built.

The 15-year-old who cannot fall asleep and the veteran who wakes gasping at 3 a.m. both deserve evidence-based information about what is happening in their brains, and real access to care that treats the root cause.

Joanna Fong-Isariyawongse does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Hate communities often flourish online for years, raising the question of how they persist. My research team has found that powerful stories keep members of a hate group galvanized, either by repeating the story over and over or by constantly adding fresh accusations and interpretations to it.

I’m a computational social scientist who studies social and political networks. My colleagues and I uncovered these trends by examining 10 years of posts, reactions and participation patterns in Facebook groups that shared antisemitic and Islamophobic content. Our findings have been accepted at the 2026 International Conference on Web and Social Media.

First, we measured who was posting and how that related to engagement on a site. Groups in which a small number of people produced most of the content tended to attract more reactions and responses. Then we looked at subjects the group members discussed – religion, immigration, geopolitics – and the kinds of stories members told about those topics, such as describing an entire group of people as criminals or warning that certain types of people are secretly taking over a country’s way of life.

When we put these pieces together, we discovered some clear patterns. Messages posted by a few very active people were strongly associated with higher site engagement in the form of likes and shares in the near term. And repetition – espousing the same ideas again and again – was an effective tactic. We also found that when many users kept adding fresh accusations, conspiracy theories and explanations, a group tended to persist. Very uniform content that used the same framing led to less engagement over time.

Different communities seemed to be drawn to different messaging patterns. In Islamophobic groups, the most prolific posters tended to repeat a narrow, consistent set of messages. Often these were religiously framed posts that portrayed Muslims as morally condemned. In antisemitic groups, the most engaged members were more likely to impart a mix of narratives, from tales of victimization to conspiracy theories about public figures.

Why it matters

Our findings suggest that hate communities can sustain themselves in various ways, so efforts to moderate them should consider these variations. If a few voices drive the conversation, removing them could quiet the noise. If new stories constantly appear from many contributors, harmful ideas may survive even if a few key online accounts are taken down. Hate networks can persist even after social media platforms ban specific groups or accounts.

It is also important to understand how stories can make prejudice feel justified and emotionally compelling. Extremist stories may claim that a group is under attack, that outsiders are dangerous or subhuman, or that violence is the only way to stay safe. Groups seen as outsiders – such as immigrants – are common targets, and they may be described as an “invasion” that threatens the nation.

What other research is being done

Researchers are finding that extremist ideas are now spreading through looser networks where many voices contribute and messaging can vary widely. That could affect whether engagement in the future still depends on consistent repetition or novelty. Some investigators are also scrutinizing how harmful language, conspiracy theories and propaganda evolve over time.

What’s next

Another important direction is tracking how hate narratives are spread by public figures and influencers, how the narratives move between online platforms, and how they surface in offline groups and efforts to organize supporters, all of which can normalize harmful ideas. My group is starting to study how this amplification works: who shares which narratives and why, which kinds of people become bridges across different online platforms, and how those roles shape which messages spread.

The Research Brief is a short take on interesting academic work.

Yu-Ru Lin's research has received federal funding, including National Science Foundation and the Department of Defense (DARPA, AFOSR, Minerva, and ONR). Any opinions, findings, and conclusions or recommendations expressed in this material do not necessarily reflect the views of the funding sources.

For decades, female sterilization has been one of the most common forms of birth control in the U.S.: 11.5% of U.S. women, ages 15-49, use female sterilization as their primary contraceptive method – nearly identical to the pill.

But the history of sterilization is also deeply entangled with coercion in the form of racial targeting, invalid consent and state control.

As a health economist and a political scientist, we wanted to better understand what factors influence women’s choices around contraception and sterilization. Our recent study found that a policy change in the 1990s which reduced the length of hospital stays for women giving birth appears to have inadvertently had a more meaningful effect on female sterilization rates in the U.S. than a landmark civil rights intervention in the 1970s.

This leads us to believe that seemingly innocuous, practical policy changes may exert greater influence on women’s reproductive choices than even public outrage over an injustice.

Looking at inflection points

In our study, we revisited Relf v. Weinberger, a 1974 civil rights case that involved the sterilization of two Black girls – the Relf sisters – without valid consent. The girls’ mother was told they were receiving a birth control shot that would temporarily prevent pregnancy. Instead, doctors subjected them to an unwanted tubal ligation surgery, in which the fallopian tubes are sealed off to permanently prevent pregnancy.

The Relf sisters were not alone: In the the early 1970s, the sisters’ case helped bring to light broader patterns in federally funded sterilization that included invalid consent and pressure tied to public benefits. Though the U.S. District Court did not find that each of these sterilizations had been coerced per se, it did find strong evidence that minors and people legally unable to consent had been sterilized with federal funds, and that sterilization was often presented as a requirement for families to maintain welfare or other government benefits. The court ruled that federally funded medical procedures require informed, uncoerced consent.

Our study examined how the public outrage, litigation and consent reforms that followed reshaped U.S. sterilization trends in the 50 years after the court ruled in favor of the Relf girls.

We then compared those effects with another, less visible inflection point in the history of female reproductive health that began in 1992, often called the “drive-through delivery” era. At this time, insurance companies instituted fixed payments to hospitals for each birth. This meant that hospitals received the same payment whether women giving birth stayed one night or two nights afterward. The practical effect was that more women who had uncomplicated births were sent home after just one night in the hospital.

The 1996 Newborns’ and Mothers’ Health Protection Act was meant to end this era, but the shift towards shorter postpartum stays persisted in an effort to cut costs.

This shortened hospital stay after birth posed a problem for women who wanted to be sterilized: Tubal ligation is logistically easy to provide immediately postpartum, while a patient is already hospitalized after giving birth. But when insurers pushed shorter postpartum stays, providers had less time to schedule and perform the procedure, meaning fewer women ended up getting the surgery.

How we did the study

We compared U.S. sterilization trends with those in other countries that had similar trends. Those countries gave us a way to estimate what U.S. sterilization patterns might have looked like if the Relf ruling or changes to hospital payment policies had not occurred. We did not look at individual medical decisions in isolation, but instead tracked patterns in how often sterilization is used across the country.

We asked a simple but important question: What actually changed sterilization practices over time? Was it the highly visible public backlash invoked by the Relf ruling? Or was it a quieter administrative change in how childbirth care was organized and paid for?

We found that the Relf case and subsequent consent reforms, including a 30-day waiting period and minimum age of 21 for federally funded sterilizations, slowed growth in U.S. female sterilization but did not reverse the broader trend. Female sterilization was still becoming more common: The national rate rose from about 5% in 1970 to about 13% in 1975. After a brief pause following the ruling and the new consent rules, it continued climbing. BY 1990, nearly 1 in 4 married women aged 15-49, were sterilized.

Nor did we see a meaningful shift in the populations most at risk of state-targeted sterilization: younger Black women in the South.

By contrast, the administrative payment reforms of the 1990s were associated with the first national declines in sterilization since the 1960s.

Why it matters

Sterilization is not inherently good or bad. It is a highly effective and often desired form of permanent contraception.

That matters now more than ever. In the 2022 case of Dobbs v. Jackson Women’s Health, the U.S. Supreme Court ruled that states can set their own abortion laws, essentially limiting abortion access for many Americans. Since this ruling, our colleagues have found increases in permanent contraception, particularly among younger adults and in states with abortion bans.

In another study, we described limiting patient choices by not providing adequate birth control options as a problem of coercion built into the very structure of the healthcare system.

The issue is not always that patients are forced into, or denied, care altogether. Often, they are offered a narrowed set of options that may look like choice, but do not fit what best meets their needs. A person with diabetes, for example, may technically have access to insulin, but only to a formulation, device or at a pharmacy location that is hard to use safely or access in their daily life.

In reproductive care, we argue that restricting options in this way can be a form of coercion, even when it is less visible.

A two-way problem

At the same time, many patients report being unable to obtain sterilization when they do want it because of Medicaid consent rules, hospital logistics, staffing limits, insurance timing or institutional restrictions.

So the problem goes two ways: Some people are pushed toward permanent contraception by a restrictive reproductive policy environment, while others are blocked from obtaining it when they want it.

That tension is precisely why sterilization is such an important issue. If rates rise or fall in response to payment incentives, discharge practices or insurance rules, it calls into question whether patient decisions are straightforward expressions of free choice. This is true for reproductive care broadly but has unique human rights implications when the method is permanent.

Our findings suggest that sterilization trends are highly responsive to policy shifts, and not only those driven by public outrage. This raises an uncomfortable question: To what extent do trends in sterilization rates truly reflect what people want, and to what extent do they reflect the choices patients were steered toward by the design of the healthcare system?

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

HIV can damage the brain and cause memory and cognitive problems. And once HIV enters the brain, it does not leave.

HIV targets a type of immune cell called helper T cells. These immune cells move throughout the body, including the brain, constantly scanning for pieces of foreign proteins called antigens that typically indicate the presence of a pathogen. When helper T cells detect antigens, they activate other immune cells to clear the infection.

Because HIV infects and depletes helper T cells, it weakens a person’s immune defenses and increases their risk of opportunistic infections, leading to AIDS.

Fortunately, there are lifesaving antiviral drugs that can control HIV and preserve helper T cells. But these antiviral drugs are unable to effectively cross into the brain and spinal cord.

My laboratory studies how helper T cells work, with the goal of developing HIV vaccines and treatments for neurodegenerative diseases. When helper T cells carry HIV into the brain, the virus hides in cells and causes persistent inflammation. This damage can accelerate brain aging.

Currently, there are no treatments to clear HIV from the brain and spinal cord. Researchers have been looking into ways to reduce the stubborn inflammation HIV causes in the central nervous system. But working with our colleagues in the Morrison Lab at UC Davis and the Raeman Lab at the University of Pittsburgh, our study found that a therapy designed to reduce inflammation in the brain and spinal cord can backfire. Instead, it increased virus levels in the brain.

Integrins are integral for viral control

T cells survey the brain and spinal cord using proteins called integrins. Embedded on the surface of cells, integrins allow immune cells to enter different areas of the body.

Researchers are studying whether blocking integrins could help combat inflammation in the brain by blocking immune cells from carrying HIV into the central nervous system. Our team tested this theory by giving rhesus macaque monkeys infected with SIV – a version of HIV that infects nonhuman primates – a multiple sclerosis drug that targets integrins.

However, when our team blocked an integrin called alpha-4 that allows T cells to migrate into the brain, we found that the amount of virus in the brain did not decrease. In fact, the viral load in some brain areas actually increased.

Bring a sniper to viral fight

We took a closer look to figure out why virus levels unexpectedly increased. Blocking the alpha-4 integrin that allow helper T cells into the brain didn’t decrease the level of those immune cells in the brain, we found. It actually reduced the numbers of another type of immune cell: killer T cells.

Unlike helper T cells, which activate other immune cells to clear an infection, killer T cells destroy infected cells. By reducing only the number of killer T cells in the brain, helper T cells continue to carry viruses into the brain, with fewer killer T cells to stop them.

To confirm our reasoning, we isolated immune cells from the brain and looked for the presence of virus and gene activity related to how well these cells were communicating with each other. We also assessed these same variables in the hippocampus, a brain region that plays a key role in regulating memory and cognition.

Both of these approaches pointed to the same conclusions. First, viral levels in the brain were higher in helper T cells following treatment. And second, the ability of killer T cells to interact with key immune cells in the brain was impaired, leading to ongoing inflammation.

Finally, we looked at mice engineered to develop T cells without the alpha-4 integrin. We found that helper T cells, which carry HIV, do not need the integrin to enter the brain, but activated killer T cells do.

Helping the killers

Reducing systemic inflammation in addition to antiviral treatment could help reduce the effects of HIV infection on the brain. Our findings suggest that HIV treatments that target immune cells with higher precision can better combat neurodegeneration instead of causing further damage.

HIV continues to rank among the top three deadliest infectious diseases worldwide. Over 40 million people globally were living with HIV in 2024, and over 22% did not have access to treatment. The Trump administration’s 2025 cuts to global funding for HIV treatments will result in higher rates of HIV infections and deaths.

More support for research on how to harness and modify the immune system to better fight HIV and other infectious diseases can improve the lives of millions of patients.

Smita Iyer owns shares in SyntherionBio. She receives funding from NIH.