Canadian scientists have developed a promising vaccine prototype against chlamydia, a study in mice suggests. Research, published in the journal Vaccine, shows that mice given the immunisation are more likely to fight off the infection.

Chlamydia is one of the most common sexually transmitted infections globally. There is currently no vaccine approved for human use. Experts say condoms are currently the best form of protection.

A team of researchers at McMaster University in Ontario gave mice two doses of the prototype vaccine, delivered through the nose. When the animals were later exposed to chlamydia, vaccinated mice had fewer copies of the bacteria replicating in their systems. Mice in the vaccinated group also had fewer signs of damage to their reproductive organs.

Public Health England says anyone under 25 who is sexually active should be tested for chlamydia every year and when they change partners.