Chlamydia is the most common sexually transmitted bacterial infection worldwide, but national screening programmes and antibiotic treatment have failed to decrease infection incidences.
The first ever chlamydia vaccine to reach phase 1 clinical trial has been found to be safe and able to provoke an immune response, according to a study published in The Lancet Infectious Diseases journal.
The randomised controlled trial of 35 healthy women demonstrates promising early signs of what could be an effective vaccine, but further trials are required to determine whether the immune response it provokes effectively protects against chlamydia infection.
Chlamydia, caused by the bacterium Chlamydia trachomatis, presents a major global health burden – with 131 million new cases occurring annually.
However, as three out of four infections are symptomless, the number of cases is likely to be underestimated. The highest number of new cases are found in teenagers and young adults.
Vaccination may be the best way to tackle the epidemic, as national treatment programmes have largely failed to curb the epidemic, despite availability of diagnostic tests and effective antibiotic treatment.
Previous studies have suggested that people infected with chlamydia develop either partial or temporary natural immunity to the pathogen, but no previous vaccines for genital chlamydia have reached clinical trials.
“Given the impact of the chlamydia epidemic on women’s health, reproductive health, infant health through vertical transmission, and increased susceptibility to other sexually transmitted diseases, a global unmet medical need exists for a vaccine against genital chlamydia,” says study author, Professor Peter Andersen, from Statens Serum Institut, Denmark.
For one in every six women infected with chlamydia, the infection travels up from the cervix and causes pelvic inflammatory disease.
This can result in chronic pelvic pain and even infertility or ectopic pregnancy, especially in the developing world, where access to treatment and screening is limited.
In addition, chlamydia is strongly associated with susceptibility to other sexually transmitted infections, particularly gonorrhoea and HIV, and chlamydia infection during pregnancy can increase the risk of adverse outcomes such as miscarriage, stillbirth, and preterm birth.
Courtesy: Lancet Infectious Diseases