Vaccines developed early in the COVID-19 pandemic still provide strong protection against severe disease, hospitalization, and death. But SARS-CoV-2, the virus that causes COVID-19, continues to mutate. Many of these mutations alter the spike protein, which the virus uses to enter and infect cells. These mutations help the virus to dodge the immune system’s attack.
Current vaccines prompt the creation of antibodies and immune cells that recognize the spike protein. However, these vaccines were developed using the spike protein from an older variant of SARS-CoV-2. This has made them less effective at preventing infection with newer variants. Researchers have found that immune cells called T cells tend to recognize parts of SARS-CoV-2 that don’t mutate rapidly. T cells coordinate the immune system’s response and kill cells that have been infected by the SARS-CoV-2 virus.
A vaccine that prompted the body to create more T cells against SARS-CoV-2 could help prevent disease caused by a wide range of variants. To explore this approach, an NIH-funded research team led by Dr. Marulasiddappa Suresh from the University of Wisconsin, Madison studied two experimental vaccines that included compounds to specifically provoke a strong T-cell response in mice.
Using mice that could be infected with SARS-CoV-2, the team tested the vaccines’ ability to control infection and prevent severe disease caused by an earlier strain of SARS-CoV-2 as well as by the Beta variant, which is relatively resistant to antibodies raised against earlier strains. The results appeared on May 17, 2022, in Proceedings of the National Academy of Sciences.
When the researchers vaccinated the mice either through the nose or by injection, the animals developed T cells that could recognize the early SARS-CoV-2 strain and the Beta variant. The vaccines also caused the mice to develop antibodies that could neutralize the early strain. However, they failed to create antibodies that neutralized the Beta variant.
The team exposed the mice to SARS-CoV-2 around 3 to 5 months after vaccination. Vaccinated mice had very low levels of virus in their lungs compared with unvaccinated mice and were protected against severe illness. This was true of infection with the Beta variant as well. This showed that the vaccine provided protection against the Beta variant despite failing to produce effective antibodies against it.
To understand which T cells were providing this protection, the researchers selectively removed different types of T cells in vaccinated mice prior to infection. When they removed CD8 (killer) T cells, vaccinated mice remained well protected against the early strain, although not against the Beta variant. When they blocked CD4 T (helper) cells, levels of both the early strain and Beta variant in the lungs and severity of disease were substantially higher than in vaccinated mice that didn’t have their T cells removed.
These results suggest important roles for CD8 and CD4 T cells in controlling SARS-CoV-2 infection. Current mRNA vaccines do produce some T cells that recognize multiple variants. This may help account for part of the observed protection against severe disease from the Omicron variant. Future vaccines might be designed to specifically enhance this T cell response.
“I see the next generation of vaccines being able to provide immunity to current and future COVID-19 variants by stimulating both broadly-neutralizing antibodies and T cell immunity,” Suresh says.
News
How Far Can the Body Go? Scientists Find the Ultimate Limit of Human Endurance
Even the most elite endurance athletes can’t outrun biology. A new study finds that humans hit a metabolic ceiling at about 2.5 times their resting energy burn. When ultra-runners take on races that last [...]
World’s Rivers “Overdosing” on Human Antibiotics, Study Finds
Researchers estimate that approximately 8,500 tons of antibiotics enter river systems each year after passing through the human body and wastewater treatment processes. Rivers spanning millions of kilometers across the globe are contaminated with [...]
Yale Scientists Solve a Century-Old Brain Wave Mystery
Yale scientists traced gamma brain waves to thalamus-cortex interactions. The discovery could reveal how brain rhythms shape perception and disease. For more than a century, scientists have observed rhythmic waves of synchronized neuronal activity [...]
Can introducing peanuts early prevent allergies? Real-world data confirms it helps
New evidence from a large U.S. primary care network shows that early peanut introduction, endorsed in 2015 and 2017 guidelines, was followed by a marked decline in clinician-diagnosed peanut and overall food allergies among [...]
Nanoparticle blueprints reveal path to smarter medicines
Lipid nanoparticles (LNPs) are the delivery vehicles of modern medicine, carrying cancer drugs, gene therapies and vaccines into cells. Until recently, many scientists assumed that all LNPs followed more or less the same blueprint, [...]
How nanomedicine and AI are teaming up to tackle neurodegenerative diseases
When I first realized the scale of the challenge posed by neurodegenerative diseases, such as Alzheimer's, Parkinson's disease and amyotrophic lateral sclerosis (ALS), I felt simultaneously humbled and motivated. These disorders are not caused [...]
Self-Organizing Light Could Transform Computing and Communications
USC engineers have demonstrated a new kind of optical device that lets light organize its own route using the principles of thermodynamics. Instead of relying on switches or digital control, the light finds its own [...]
Groundbreaking New Way of Measuring Blood Pressure Could Save Thousands of Lives
A new method that improves the accuracy of interpreting blood pressure measurements taken at the ankle could be vital for individuals who are unable to have their blood pressure measured on the arm. A newly developed [...]
Scientist tackles key roadblock for AI in drug discovery
The drug development pipeline is a costly and lengthy process. Identifying high-quality "hit" compounds—those with high potency, selectivity, and favorable metabolic properties—at the earliest stages is important for reducing cost and accelerating the path [...]
Nanoplastics with environmental coatings can sneak past the skin’s defenses
Plastic is ubiquitous in the modern world, and it's notorious for taking a long time to completely break down in the environment - if it ever does. But even without breaking down completely, plastic [...]
Chernobyl scientists discover black fungus feeding on deadly radiation
It looks pretty sinister, but it might actually be incredibly helpful When reactor number four in Chernobyl exploded, it triggered the worst nuclear disaster in history, one which the surrounding area still has not [...]
Long COVID Is Taking A Silent Toll On Mental Health, Here’s What Experts Say
Months after recovering from COVID-19, many people continue to feel unwell. They speak of exhaustion that doesn’t fade, difficulty breathing, or an unsettling mental haze. What’s becoming increasingly clear is that recovery from the [...]
Study Delivers Cancer Drugs Directly to the Tumor Nucleus
A new peptide-based nanotube treatment sneaks chemo into drug-resistant cancer cells, providing a unique workaround to one of oncology’s toughest hurdles. CiQUS researchers have developed a novel molecular strategy that allows a chemotherapy drug to [...]
Scientists Begin $14.2 Million Project To Decode the Body’s “Hidden Sixth Sense”
An NIH-supported initiative seeks to unravel how the nervous system tracks and regulates the body’s internal organs. How does your brain recognize when it’s time to take a breath, when your blood pressure has [...]
Scientists Discover a New Form of Ice That Shouldn’t Exist
Researchers at the European XFEL and DESY are investigating unusual forms of ice that can exist at room temperature when subjected to extreme pressure. Ice comes in many forms, even when made of nothing but water [...]
Nobel-winning, tiny ‘sponge crystals’ with an astonishing amount of inner space
The 2025 Nobel Prize in chemistry was awarded to Richard Robson, Susumu Kitagawa and Omar Yaghi on Oct. 8, 2025, for the development of metal-organic frameworks, or MOFs, which are tunable crystal structures with extremely [...]
