“If you could introduce a protective vaccine, you could break that cycl”
Researchers discovered the vaccine triggered an immune response during preliminary tests on 35 women.
Fresh trials will be carried out to learn whether it can wholly protect against infection, but scientists believe it is an “important first step” in tackling the STI.
Professor Robin Shattock, from Imperial College London, said: “The findings are encouraging as they show the vaccine is safe and produces the type is safe and produces the type of immune response that could potentially protect against chlamydia.”
Chlamydia is the most common bacterial STI in the world and accounts for almost half of all sex-related infections in England.
The infection is currently treated with antibiotics, but people could still catch it again.
As many as three in four cases show no symptoms, leading some to think they are not infected.
Dr Shattock continued: “The major issue with chlamydia is the long-term consequences.
“It is very treatable if identified, but as many people don’t have symptoms it can be missed, and the biggest problem is that it can go on to cause infertility in women.
“One of the problems we see with current efforts to treat chlamydia is that despite a very big screening, test and treat programme, people get repeatedly re-infected.”
The expert added: “If you could introduce a protective vaccine, you could break that cycle.”
Young Brits are still among the most likely to catch the virus, with many practising unprotected sex.
New research suggested that randy revellers heading off to Spain faced even more risk of catching the disease where diagnosed cases rocketed by 527% in just five years.