Measles Vaccine T Cells Recognize Nipah Virus, Suggesting Broader Protection

A recent study reveals that T cells generated by the measles vaccine have the ability to recognize the Nipah virus, a deadly pathogen related to measles. This discovery highlights the potential for vaccines that provide immunity against multiple viruses within the paramyxovirus family simultaneously.

T cells are a key component of the immune system, capable of combating infections and slowing tumor growth. Scientists at the La Jolla Institute for Immunology (LJI) have investigated how T cells identify paramyxoviruses, which include both the measles virus and the Nipah virus. Paramyxoviruses pose significant pandemic risks due to their contagiousness and lethality.

Importance of Broad T Cell Immunity Against Viral Threats

“No one knows which particular viral species or strain of a virus might be responsible for an outbreak, as we’ve seen in the recent cases of Andes hantavirus,” stated LJI Professor Alessandro Sette, Dr.Biol.Sci., who led the study. LJI Research Assistant Professor Alba Grifoni, Ph.D., co-leader of the research, added, “Activating T cells can be your first line of defense when you don’t know what’s going to be thrown at you.”

The study, published in Cell Reports Medicine, received funding from the National Institutes of Health’s National Institute of Allergy and Infectious Diseases (NIAID) and the Coalition for Epidemic Preparedness Innovations (CEPI).

How Conserved Viral Epitopes Facilitate Broad Immune Responses

T cells belong to the adaptive immune system, which tailors responses to specific threats by recognizing molecular markers called epitopes. While epitopes usually differ between pathogens, some remain conserved within related virus families despite viral evolution. This conservation allows certain T cells to cross-react with different viruses sharing similar epitopes.

Cross-Reactive T Cells and Viral Family Recognition

During the COVID-19 pandemic, LJI researchers including Sette, Grifoni, Assistant Professor Daniela Weiskopf, Ph.D., and Professor Shane Crotty, Ph.D., demonstrated that cross-reactive T cells can detect similarities across coronaviruses. Individuals previously infected with common cold coronaviruses may possess T cells capable of recognizing SARS-CoV-2. Further research by Sette and Grifoni indicated that cross-reactive T cells might also defend against the Lassa virus and other arenaviruses, suggesting a broader protective potential for vaccines and treatments activating these cells.

Measles Vaccine-Induced T Cells and Nipah Virus Recognition

In the United States, measles cases have increased as vaccination rates declined, with 2,033 confirmed cases reported in 2026 so far—on track to surpass 2025 totals. Globally, measles remains a threat, while Nipah virus, transmitted by bats and prevalent in Southeast Asia, is rare but highly fatal, with death rates between 40 and 75 percent. “Outbreaks are becoming more and more frequent, especially in the Malaysian region,” noted Grifoni.

The LJI team’s findings suggest that cross-reactive T cells could be a valuable defense against paramyxoviruses such as measles and Nipah.

Mapping the Measles Vaccine T Cell Response

Researchers collaborated with LJI’s John and Susan Major Center for Clinical Investigation to analyze T cells from blood samples of 31 individuals vaccinated with the MMR vaccine, which protects against measles, mumps, and rubella viruses. These samples contained T cells primed to respond to measles infection.

LJI Postdoctoral Fellow Alison Tarke, Ph.D., and Senior Staff Scientist Ricardo Da Silva Antunes, Ph.D., led experiments to identify the specific T cell epitopes on the measles virus. “Even though measles has been studied for quite some time, and there is a vaccine for measles, there was not a lot known about the specific T-cell response elicited by the measles vaccine,” said Sette.

Shared Epitopes Between Measles and Nipah Viruses

Subsequent tests examined whether these measles-trained T cells could also respond to Nipah virus, despite none of the participants having prior Nipah exposure. The researchers discovered that some T cells cross-reacted with Nipah virus due to conserved epitopes shared between the two paramyxoviruses.

“Focusing immune responses on these conserved regions could have a broad, protective capacity for the whole viral family,” Sette explained. This research represents the first mapping of T cell epitopes on Nipah virus, identifying a shared epitope on the viral fusion (“F”) protein recognized by many cross-reactive T cells.

Sette added, “It appears that if someone is vaccinated against measles, their T cells will have some degree of cross-reactivity to Nipah. That raises the possibility that during a Nipah outbreak, one could perhaps vaccinate people with a measles vaccine, and this cross-reactivity could potentially offer some benefit.”

Reference: “Comprehensive mapping of human CD4+ T cell epitopes for Nipah and measles as prototype Paramyxoviruses” by Alison Tarke et al., published 2 June 2026 in Cell Reports Medicine. DOI: 10.1016/j.xcrm.2026.102838.