Chlamydia trachomatis is the most commonly reported sexually transmitted infection in the United States. According to the Centers for Disease Control and Prevention, the bacterial disease was responsible for nearly 3 million new infections in the U.S. in 2017. The World Health Organization says chlamydia is thought to have caused at least 127 million new infections worldwide in 2016. Now, team of British and Danish scientists believe that they may have created a vaccine for the sexually transmitted infection that is safe and effective.
According to the team’s report, published in the Lancet Infectious Diseases medical journal, two vaccine candidates were tested in a trial conducted at London’s Hammersmith Hospital involving 35 women between the ages of 19 and 35. Over a period of four months, fifteen women were dosed three times with a shot of one of the vaccines while the remaining five received placebo shots. In the final month, each participant took the same medication or placebo twice through a nasal spray.
The researchers found that, based on tests of their blood and mucus samples taken from the vagina, the women had an immune response to chlamydia regardless of the vaccine taken. There were no serious side-effects from either the shot or the nasal spray. While only 32 of the women had taken all five doses by the end of the trial, data from all the women was included in the final results.
This study is the first clinical trial for a vaccine for genital chlamydia. Chlamydia is almost always treatable with antibiotics, but three out of every four cases don’t include symptoms, so the person may not even know that they are infected. Even after treatment, many people who are diagnosed end up getting re-infected. A protective vaccine could break that cycle and insulate more people from getting the infection in the first place.