Even after the fever and cough are gone, some people continue to feel unwell following a case of COVID-19 or seasonal flu.  Tulane National Biomedical Research Center (NBRC) scientist Dr. Xuebin Qin and colleagues set out to understand which long-term effects are shared between COVID-19 and the flu, and which may be unique to COVID-19.

The Study

Their new study, published in Frontiers in Immunology, compared how SARS-CoV-2 (the virus that causes COVID-19) and influenza affect the body after the acute infection has resolved. Using a carefully controlled mouse model, the team examined lung and brain tissue weeks after infection to identify what kind of biological “footprint” each virus leaves behind. While animal models cannot capture every aspect of human disease, they allow researchers to closely examine biological changes that are difficult to study in patients. The findings may help explain why both COVID-19 and the flu can leave behind lasting lung problems, while long COVID is more often linked to neurological symptoms such as brain fog, fatigue and mood changes.

When researchers studied the lungs, they saw a similar pattern after both infections. Immune cells remained more active than normal instead of fully standing down, and there was an increased buildup of collagen, a protein associated with scarring. These changes can stiffen lung tissue and make breathing feel harder, offering a potential biological explanation for why some people have persistent shortness of breath after respiratory infections.

What Was Discovered

A key difference emerged when the team examined how the lungs were trying to heal. After influenza, the lungs showed signs of switching into repair mode: specialized cells moved into damaged areas to rebuild the lining of the airways. After COVID-19, that repair response appeared to be limited. This suggests that SARS-CoV-2 may interfere with the lung’s natural healing process, potentially setting the stage for longer recovery and lasting respiratory symptoms.

The most striking findings came from the brain. Even though neither virus was detectable in brain tissue at the time of analysis, mice that had recovered from COVID-19 still showed signs of ongoing brain inflammation. The researchers also observed small areas of bleeding earlier in the infection, pointing to potential damage to tiny blood vessels.

Gene expression analysis revealed that inflammatory signaling remained elevated, and that key pathways related to serotonin and dopamine regulation were disrupted. These chemical systems are closely tied to mood, cognition and energy levels, which are frequently affected in people with long COVID. In contrast, brains from influenza-infected animals showed far fewer of these persistent changes.

“In both infections, we observed lasting lung injury,” Qin noted. “But long-term effects in the brain were unique to SARS-CoV-2. That distinction is critical to understanding long COVID.”

Connecting Infection, Blood Vessels and The Brain

The findings suggest that inflammation and damage to small blood vessels in the brain may play a role in long-lasting neurological symptoms. Even without the virus present, these changes can affect how brain cells communicate.

By clearly defining these biological changes, researchers at Tulane NBRC are helping to create a roadmap for future clinical studies. The patterns they identified could guide how clinicians monitor patients after infection, which biomarkers to track, and which pathways might be most promising for new therapies aimed at preventing or reducing lasting damage.

Why This Matters for Patients and Future Therapies

By directly comparing COVID-19 with flu in the same experimental framework, Tulane NBRC investigators provide a clearer picture of which long-term issues are shared across severe respiratory infections, and which are specific to SARS-CoV-2. That knowledge can help clinicians and scientists focus their efforts on where they are most likely to make a difference for patients still waiting to feel fully recovered.

Measles is Making a Comeback

Measles was declared eliminated in the U.S. in 2000, but that progress is now at risk. As vaccination rates have dropped, measles cases have risen, with the country seeing the highest levels since 1991. The disease remains highly contagious and can lead to serious complications, especially for young children.

Why Explore a Treatment?

The MMR vaccine is highly effective and remains the best protection against measles, and it is still highly effective. With increasing cases, researchers are exploring a treatment option for people who are infected.

What Researchers are Testing

At Texas Biomedical Research Institute in San Antonio, researchers will test a potential measles treatment using monoclonal antibodies. This lab-made protein is designed to interfere with the virus before it can enter cells and spread.

Unlike many antiviral drugs which target viruses after they have already entered cells, monoclonal antibodies can block infection earlier in the process. They attach to specific parts of the virus and stop it from getting into the body’s cells. Monoclonal antibodies may also help reduce viral load and support the immune response after infection has begun.

Next Steps

The antibody being studied, called mAb 77, was developed by researchers at the La Jolla Institute for Immunology and Columbia University. It showed promise in lab and rodent studies, and Texas Biomed will now test it in juvenile rhesus monkeys. If those results are consistent, the treatment could eventually move into human clinical trials.

Will this Treatment Replace Vaccines?

Measles once caused millions of deaths each year before the vaccine became widely available. Today, the vaccine can prevent most cases after two doses. Researchers say a treatment could be helpful especially for those who are immunocompromised or too young to be vaccinated, but the larger lesson is clear: vaccination remains the simplest and most effective way to stop measles from spreading in the first place.

A study published in Nature may point to a promising new path in the fight against pediatric HIV. Led by Mauricio A. Martins, PhD, and Amir Ardeshir, DVM, MPVM, PhD, with key work conducted at the California National Primate Research Center and contributions from Tulane National Biomedical Research Center, researchers showed that a single gene therapy injection given at birth could provide long-term protection against HIV by taking advantage of a unique window when a newborn’s immune system is more tolerant.

The study used an adeno-associated virus, or AAV, to deliver genetic instructions for producing broadly neutralizing antibodies, which are powerful antibodies capable of recognizing multiple strains of HIV. The therapy essentially turns muscle cells into antibody-producing “micro-factories,” offering a potential way to provide lasting protection without repeated treatments or boosters.

Timing proved critical. Infant rhesus macaques treated at birth maintained antibody expression for more than three years and were protected in models that mimic HIV transmission through breastfeeding and sexual exposure. Older recipients were less protected, underscoring the importance of early intervention and the role of the newborn immune system’s natural window of tolerance.

This approach could help address mother-to-child HIV transmission, which remains a major global health challenge, especially in regions where access to follow-up care and long-term treatment can be limited. A one-time intervention given at birth could offer a more practical and scalable prevention strategy for infants at risk.

More research is needed before this approach can be tested in humans, including studies to determine how it may work against different HIV strains. Still, the findings offer hope for a cost-effective, long-lasting strategy to help reduce pediatric HIV and may eventually inform similar approaches for other infectious diseases, including malaria.

The fight against HIV has seen remarkable progress, thanks in large part to foundational research at the Washington National Primate Research Center (WaNPRC). While recent headlines rightfully celebrate the FDA approval of new HIV drugs like Yeztugo (lenacapavir, for pre-exposure prophylaxis, PrEP) and Sunlenca (for treatment), the story behind these breakthrough drugs began years earlier in the labs of WaNPRC. 

WaNPRC’s involvement in HIV research stretches back decades. In the mid-1990s, Dr. Che-Chung Tsai demonstrated that an experimental drug, tenofovir, could completely protect pigtail macaques from Simian Immunodeficiency Virus (SIV), a virus closely related to HIV and causes AIDS, when given before or after exposure. This study directly led to the development of Truvada, a drug that has reduced HIV transmission globally for over 20 years, by Gilead Pharmaceuticals. Building on this success, researchers turned to WaNPRC’s expertise again to test lenacapavir (now Yeztugo/Sunlenca) in nonhuman primates, ensuring its safety and effectiveness before human trials. 

Why non-human primates? Female pigtail macaques are especially valuable for HIV research because their reproductive biology closely mirrors that of humans, making them ideal for studying antivirals and vaccines that could prevent vaginal and rectal transmission of the virus—key routes for HIV in both men and women. This translational research bridge is critical because findings in the lab must be validated in nonhuman primates before moving to human studies. 

The impact of these advancements is profound. With 1.1 million Americans living with HIV and persistent challenges in PrEP access and adherence, a twice-yearly injection like Yeztugo could significantly boost prevention efforts. Meanwhile, Sunlenca offers new hope for those already living with HIV, used in combination with other therapies. 

WaNPRC’s work isn’t done. Researchers like Dr. Rodney Ho are developing even longer-acting HIV drug combinations, with some already entering human trials. These innovations promise to further extend life expectancy, reduce healthcare burdens, and improve quality of life for patients. 

The stories of Yeztugo and Sunlenca are a testament to the essential role of primate research centers like WaNPRC in turning scientific discoveries into real-world solutions. Their ongoing commitment to this research and key role in the development of these next generation HIV treatments and preventatives will continue to save lives and shape the future of global health. 

How NPRC Research Accelerated HIV Advances From 2020–2025

From breakthroughs in prevention to promising treatments, the National Primate Research Centers (NPRCs) have played a crucial role in advancing HIV research. Working with nonhuman primates, the closest biomedical model to humans, NPRC researchers have tackled some of HIV’s biggest challenges: viral persistence, brain invasion, co-infections and the limits of current therapies. Together, these discoveries mark some of the most significant progress toward long-term remission and potential cures in decades.

Strengthening Vaccines and Early Prevention

NPRC advances include efforts to block infection before it starts. Researchers at the Emory National Primate Research Center (ENPRC) at Emory University showed that an Env-plus-Gag HIV vaccine regimen in rhesus macaques provided durable protection from SHIV, the simian version of HIV, even when neutralizing antibody levels were low. This finding expanded thinking around the types of immune responses a successful vaccine must generate.

At the same time, Oregon NPRC scientists found that leronlimab, a monoclonal antibody that blocks the CCR5 co-receptor, effectively prevented SHIV infection in nonhuman primate models. Already tested in human studies for viral suppression, the antibody also showed promise as a PrEP-style preventive option.

Targeting HIV’s Hidden Reservoirs

Because HIV hides in tissues the immune system can’t easily reach, several NPRC studies focused on uncovering and disrupting these viral reservoirs. ENPRC scientists discovered that the anti-inflammatory molecule IL-10 helps HIV-infected cells survive in lymph nodes. Blocking IL-10, alongside antiretroviral therapy (ART), reduced the number of infected reservoir cells, marking an important step toward weakening HIV’s stronghold.

Researchers at Emory NPRC also identified specialized follicle-infiltrating NK cells capable of entering B-cell follicles in lymph nodes, one of HIV’s most protected hiding places. These findings point toward future therapies that could guide immune cells directly into viral reservoir sites.

Additional “shock and kill” studies at Wisconsin NPRC showed that both latency-reversing drugs and checkpoint inhibitor combinations can reactivate dormant virus while nonhuman primates are on ART, laying groundwork for strategies that flush HIV out of hiding.

Immune-Based Therapies Move Toward Functional Cure

By 2024, several NPRC collaborations delivered results that brought the field closer to long-term remission without lifelong treatment. A landmark study testing N-803 (IL-15 superagonist) plus broadly neutralizing antibodies achieved long-lasting viral control in most SHIV-infected macaques even after ART was stopped. The findings have now progressed to early-phase human clinical trials.

Emory NPRC researchers also identified a particularly potent subset of CD8⁺ T cells (TCF1⁺CD39⁺) that excel at controlling SIV and resisting exhaustion. The importance of these cells has been confirmed also in people with HIV and may become powerful tools in future immunotherapies.

Understanding HIV in the Brain

Another major advancement came from California NPRC, where researchers discovered how HIV enters and persists in the brain. Their work showed that CD4 T cells can inadvertently carry virus into neural tissue, helping explain why HIV-associated neurocognitive disorders persist even when ART is effective.

Addressing Co-Infections and Real-World Treatment Needs

HIV rarely exists in isolation. In 2025, Texas Biomed and the Southwest NPRC demonstrated that a promising tuberculosis therapy did not interfere with combined antiretroviral therapy (cART) used to treat HIV, supporting its safe use in people co-infected with HIV and TB. Because the drug is already FDA-approved for use in cancer patients, it could accelerate potential approval for TB/HIV treatment compared to developing an entirely new drug.

A Path Toward Remission

Building on these advances, Emory NPRC researchers reported one of the strongest signals yet that a functional cure for HIV may be achievable. In a stringent SIV model, a targeted combination therapy, blocking two negative regulators of the immune system, IL-10 and PD-1, enabled durable control of viral rebound in 9 of 10 nonhuman primates for six months after ART ended, an unprecedented result that strengthens the path toward future human trials. This is a direct proof of concept that the immune system can be harnessed with immune-based interventions to control HIV.

The Bottom Line

Between 2020 and 2025, NPRC research meaningfully advanced the HIV landscape. Through innovative vaccine approaches, better understanding of persistence, targeted immune strategies and real-world treatment insights, the NPRCs have laid essential groundwork for an era in which long-term HIV remission, and ultimately a cure, becomes an attainable goal.

An update to From SIV to HIV: Emory NPRC Research Paves Way for Potential Cure 

In 2025, researchers at the Emory Vaccine Center and the Emory Primate Center led by Dr. Paiardini have made two significant advancements in the pursuit of a cure for HIV. Using nonhuman primates and the simian immunodeficiency virus (SIV), the best model for HIV infection in humans, the team identified a treatment that can reduce the viral reservoir – infected cells that are not eliminated by the immune system – a key obstacle for curing HIV.  

Recent studies strongly suggest that a protein called Bcl-2 favors the survival of cells infected with HIV. Bcl-2 also favors the survival of cancer cells. There is a clinically approved medication for cancer patients, Venclexta, that blocks Bcl-2 and promotes cell death. 

For the first time, the Emory Vaccine Center team showed that giving Venclexta to SIV-infected nonhuman primates eliminates a significant portion of the viral reservoir. Based on these exciting results, a clinical trial was approved to treat people living with HIV starting antiretroviral therapy (ART) with Venclexta. 

In a second study, Dr. Paiardini’s group tested an intervention where two brakes of the immune system, IL-10 and PD-1, were removed by antibodies blocking their functions. This is a follow up study to recently published work from Dr. Sekaly and Dr. Paiardini. This intervention, repeated in two phases over a 3-year-long study, resulted in 100% of the animals controlling viral rebound at very low levels for months despite no longer receiving ART. Even more exciting, the treatment also reduced the size of the viral reservoir by nearly 100-fold. 

Now, the scientists at the Emory Vaccine Center and Emory Primate Center are seeking funds to perform the next step of this life-saving research and take the fight against HIV across the finish line.  

With additional funding, they plan to test a combined intervention where Venclexta will reduce the size of the viral reservoir and the aIL-10 and aPD-1 will work together to eliminate all of the infected cells by increasing the strength of the immune system. 

This research has the potential to improve the lives of more than 40 million people living with HIV worldwide. 

Emory University researchers have made a significant advancements in the pursuit of an HIV cure. One of the teams, led by Dr. Rafick Sekaly and Dr. Mirko Paiardini, demonstrated unprecedented control of simian immunodeficiency virus (SIV) replication and decay of viral reservoirs in nonhuman primates.

Key Findings:

The study, which was published in Nature Immunology, combined a stringent model of SIV infection with interruption of antiretroviral therapy (ART) and targeted immune intervention.

Researchers identified mechanisms of action for PD1 and IL-10, molecules known to regulate HIV persistence and immune dysfunction.

Nine of ten monkeys that received combination treatment showed durable control of viral rebound lasting six months after stopping ART.

Implications for HIV Treatment:

This research represents a major step forward in developing a functional cure for HIV, potentially improving the lives of 39 million people living with the disease worldwide. The study’s success stems from more than 15 years of work on PD1 and IL-10, which could lead to improved approaches for restoring deficient immune systems and controlling chronic infections.

Collaborative Effort:

The study highlights the power of collaboration between academia and industry. Merck, as an industry partner, developed reagents specifically designed to target PD1 and IL10 molecules in nonhuman primate models.

Up Next:

The research team is further investigating innate immune, metabolic and epigenetic pathways associated with controlling the virus after ending treatment. Their goal is to develop interventions that can induce an immune response capable of long-term control of HIV and SIV without ART.

This breakthrough brings us one step closer to a potential HIV cure, offering hope to millions affected by the disease worldwide.

A study involving Oregon Health & Science University (OHSU), OHSU, the Oregon, Tulane and Washington National Primate Research Centers, the University of Washington and the University of Pittsburgh has revealed a promising approach to developing a universal influenza vaccine. This innovative “one and done” vaccine could potentially provide lifetime immunity against evolving flu viruses. 

The research, published in Nature Communications, tested an OHSU-developed vaccine platform against the H5N1 avian influenza virus, considered a likely candidate for the next pandemic. Remarkably, the vaccine was based on the 1918 flu virus yet still provided protection against the modern H5N1 strain. 

Key findings from the study include: 

• Six out of 11 vaccinated nonhuman primates survived exposure to H5N1, while all unvaccinated primates succumbed to the virus. 

• The vaccine targets the internal structural proteins of the virus, which remain relatively unchanged over time, unlike the constantly mutating outer surface proteins. 

• This approach could be effective against other mutating viruses, including SARS-CoV-2. 

The vaccine platform, which uses cytomegalovirus (CMV) as a vector, was originally developed to fight HIV and tuberculosis. It works by inducing an immune response from the body’s T cells, specifically targeting the virus’s internal structure. 

Dr. Jonah Sacha, professor and chief of the Division of Pathobiology at OHSU’s Oregon National Primate Research Center and the study’s senior author, believes this breakthrough could lead to a universal flu vaccine within five to ten years. The same platform is already in clinical trials for HIV and shows promise for targeting specific cancer cells. 

This research represents a significant advancement in addressing infectious diseases and could revolutionize our approach to vaccine development for rapidly evolving viruses. 

Researchers at Texas Biomedical Research Institute (Texas Biomed) have made significant progress in the fight against tuberculosis (TB) and HIV co-infection. The team, led by Professor Smriti Mehra, Ph.D., has demonstrated that a promising TB therapy does not interfere with combined antiretroviral therapy (cART) used to treat HIV. 

A Critical Breakthrough 

Tuberculosis remains a global health concern, causing over 1.3 million deaths annually. For individuals with HIV, TB poses an even greater threat due to their compromised immune systems. The new therapy targets an immune system protein called IDO (Indoleamine-2,3-dioxygenase), which normally suppresses immune responses. 

How It Works 

By inhibiting IDO, the therapy aims to enhance the body’s ability to fight TB. This approach has already shown success in cancer treatments and has demonstrated improved control of TB when used alongside antibiotics. 

Safe for HIV Patients 

The study, conducted with nonhuman primates at the Southwest National Primate Research Center with both TB and simian immunodeficiency virus (SIV), revealed that the IDO inhibitor does not interfere with cART. This is crucial for developing a treatment that can help patients battling both HIV and TB. 

Next Steps 

Researchers plan to study how the inhibitor performs when used in conjunction with both antibiotics and cART together – the standard treatment regimen for patients with HIV and active TB. Long-term studies are also needed to confirm the absence of unintended side effects. 

Potential for Rapid Approval 

The IDO inhibitor is already FDA-approved for use in cancer patients, which could accelerate its potential approval for TB/HIV treatment compared to developing an entirely new drug. This research represents a significant step forward in addressing the challenges of TB and HIV co-infection, offering hope for more effective treatments in the future.

Scientists at Emory University have made an exciting discovery that could bring us one step closer to curing HIV. Their research, published in Nature Immunology, focuses on a special type of immune cell called CD8+ T cells. 

What’s the big deal?
The researchers identified a unique subset of CD8+ T cells in lymph nodes that are particularly effective at fighting simian immunodeficiency virus (SIV), which is similar to HIV in humans. These cells, called TCF1+CD39+CD8+ T cells, work differently from typical T cells but pack a powerful punch against the virus. 

Why is this important?
“Harnessing CD8+ T cell functions is imperative toward an HIV cure,” says Mirko Paiardini, PhD, Microbiology and Immunology division chief at the Emory National Primate Research Center. Currently, 39 million people worldwide live with HIV, and while existing treatments are effective in blocking the replication of the virus, they don’t eliminate the virus completely. 

How do these special T cells work?
These newly discovered T cells are unique because they: 

• Are better at controlling the virus 

• Reduce viral reservoirs (cells and places where the virus hides in the body) 

• Can maintain their effectiveness without getting “exhausted” 

• Have features that allow them to keep reproducing and fighting 

What’s next?
The Emory team plans to: 

• Study these T cells at different stages of infection 

• Explore how well they respond to potential HIV cure treatments 

• Investigate their effectiveness in other parts of the body beyond lymph nodes 

The bigger picture:
This research is part of a larger effort called ERASE HIV, which aims to develop innovative therapies to eliminate or control HIV without the need for lifelong medication. The team is also working with community organizations to share their findings and progress with those affected by HIV.  

While there’s still much work to be done, this discovery offers new hope in the ongoing battle against HIV and brings us closer to the possibility of a cure.