Scientists have found immune T cells that can fight both measles and the deadly Nipah virus. This discovery suggests that vaccines could be developed to protect against several emerging viruses at once.
T cells are powerful parts of the immune system. They help fight infections and can even slow tumor growth. Researchers at La Jolla Institute for Immunology (LJI) learned how T cells recognize paramyxoviruses, a group that includes measles and Nipah.
Paramyxoviruses are a potential pandemic threat. Measles spreads easily, and Nipah virus is often fatal. The new findings show a way T cells could protect people from these dangerous viruses.
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Start Your News DetoxInstead of creating protection for one virus at a time, scientists found that boosting "cross-reactive" T cells could defend against the whole paramyxovirus family. This broad protection would be vital when the next outbreak is unknown.
Why Broad T Cell Protection Matters
LJI Professor Alessandro Sette explained that no one knows which virus strain will cause the next outbreak. He mentioned recent cases of Andes hantavirus as an example.
LJI Research Assistant Professor Alba Grifoni added that activating T cells can be a first defense when facing an unknown threat.
The Cell Reports Medicine study was supported by the National Institutes of Health and the Coalition for Epidemic Preparedness Innovations (CEPI).
How Shared Viral Features Allow Broad Immunity
T cells are part of the adaptive immune system, meaning they learn to recognize specific threats. Each T cell looks for tiny molecular markers called "epitopes" to tell the difference between the body's own cells and a threat. Usually, epitopes from different pathogens look very different.
However, some features stay the same within related virus families as viruses evolve. This is where immunologists find an opportunity. LJI researchers have shown that some T cells can "cross-react" with different viruses if those viruses share similar epitopes.
During the COVID-19 pandemic, LJI scientists found that cross-reactive T cells could detect similarities among different coronaviruses. Someone who had a common cold coronavirus might already have T cells ready to recognize SARS-CoV-2, the virus causing COVID-19.
Sette and Grifoni later showed that cross-reactive T cells might also protect against the deadly Lassa virus and the larger arenavirus family. Their work suggests that future vaccines could activate these T cells to guard against several dangerous viruses at once. These studies highlight why cross-reactive T cells are important for stopping emerging viruses.
Measles Vaccine T Cells Show Promise Against Nipah Virus
Measles cases have increased in the United States as vaccination rates have dropped. In 2026 alone, the U.S. reported 2,033 confirmed measles cases. This number is on track to surpass the total cases from 2025.
Measles is still a global threat. In Southeast Asia, Nipah virus is another related danger. Spread by bats, Nipah virus is rare but can be very deadly, with a fatality rate of 40% to 75%. Grifoni noted that outbreaks are becoming more frequent, especially in Malaysia.
The new LJI findings suggest that cross-reactive T cells could be a key tool against the dangerous paramyxovirus family.
Decoding the Measles Vaccine’s T Cell Response
The research team studied T cells from blood samples of 31 people. All participants had received the MMR vaccine, which protects against measles, mumps, and rubella. Their blood samples contained T cells ready to respond to measles.
The researchers first looked at how these T cells identified measles virus. LJI Postdoctoral Fellow Alison Tarke and Senior Staff Scientist Ricardo Da Silva Antunes mapped the T cell epitopes on measles virus.
Sette noted that even though measles has been studied for a long time and a vaccine exists, little was known about the specific T-cell response from the measles vaccine.
Shared Measles–Nipah Targets Could Guide Future Pandemic Vaccines
Alison Tarke and the LJI team then tested if the same T cells responded to Nipah virus. Blood tests showed that none of the participants had ever been infected with Nipah. Their T cells had not learned to recognize Nipah virus epitopes before.
Despite this, the researchers found that some T cells trained to fight measles could also detect Nipah virus. These T cells cross-reacted because both paramyxoviruses shared "conserved" epitopes.
Sette explained that focusing immune responses on these conserved regions could offer broad protection for the entire viral family.
This study is the first to map T cell epitopes on Nipah virus. The researchers also found a specific epitope shared by measles and Nipah viruses: a part of the viral fusion, or "F," protein. Many cross-reactive T cells recognized this small, conserved structure.
Sette concluded that if someone is vaccinated against measles, their T cells will have some cross-reactivity to Nipah. This suggests that during a Nipah outbreak, a measles vaccine might offer some benefit.
Deep Dive & References
Comprehensive mapping of human CD4+ T cell epitopes for Nipah and measles as prototype Paramyxoviruses - Cell Reports Medicine, 2026
