There are promising signs for a chlamydia vaccine after recent clinical trials.

The common, sexually-transmitted disease chlamydia is caused by a bacterial infection and can be treated with antibiotics, but three-quarters of cases do not have any symptoms which makes it difficult to screen and treat.

In a recent initial trial, a small group of women were given a new vaccine, which triggered an immune response.

No previous vaccine to protect against chlamydia has reached clinical trials, and this one will still need more study to find out whether the immune response translates into immunity.

Although the vaccine provokes an immune response, whether this translates into protective immunity remains unclear.

First author Dr Helene Juel says: “Studies of antibodies in mice have found that antibodies in the vagina are the first line of defence against chlamydia infection, which suggests they are key to how effective the new vaccine may be.”

“In our trial, significantly increased concentrations of these antibodies were found.

“Many more years of research are needed before this vaccine is marketed, we are planning the next stage of research – a phase 2a study.”

The research is accessible here.