BAR HARBOR — Maine’s Jackson Laboratory is announcing the first mouse strain aimed at helping researchers find treatments for typhoid fever.

The biomedical facility says the specialized mice will allow researchers to develop new vaccines and treatments for typhoid fever, a serious threat to health in the developing world.

The life-threatening illness strikes more than 21 million people, mainly in Africa, Asia and Latin America each year. Most patients have limited access to antibiotics, and currently available vaccines for typhoid prevention offer only limited effectiveness.

The mouse has an immune system that mimics that of a human, which opens the door to further research on treatments and vaccines.

The Jackson Laboratory is an independent, nonprofit biomedical research institution based in Bar Harbor, with a facility in Sacramento, Calif.