Experimental vaccine protects monkeys from blinding trachoma

A weakened strain of Chlamydia trachomatis bacteria can be used as a vaccine to prevent or reduce the severity of trachoma, the world’s leading cause of infectious blindness, suggest findings from a National Institutes of Health study in monkeys.

The researchers tested their vaccine concept in a series of experiments. First they infected six cynomolgus macaques with the strain of C. trachomatis that they had weakened by removing a small piece of DNA. The scientists observed that the monkeys spontaneously cleared the infection within 14 days with no or minimal signs of ocular disease.

The animals were then exposed twice more to the weakened strain at four- and eight-week intervals, but the animals still showed no signs of trachoma despite being infected.

Read more at National Institute of Allergy and Infectious Diseases