Is there a vaccine for chlamydia?

Not yet. But in 2019 a potential vaccine

was found safe in an early trial. Experts are urging more human trials

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  • Chlamydia, the most common bacterial STI, often has no symptoms.
  • A potential vaccine for chlamydia was found safe in an early trial.
  • This is a welcome development because untreated chlamydia can damage a woman’s fertility.
  • Experts are urging more human trials for the vaccine.

The first major attempt at a vaccine against chlamydia — the most common reportable bacterial sexually transmitted infection (STI), which is asymptomatic in most people but can cause serious complications for women — has passed a hurdle.

In a recent issue of commentary accompanying the Lancet study saying a vaccine against the disease could have a significant public-health effect. Experts are urging further human clinical trials.

Why is a chlamydia vaccine important?

Chlamydia is one of the most common STIs, with an estimated 131 million people infected worldwide each year. In the United States, it’s the most frequently reported STI caused by bacteria. According to the Centers for Disease Control and Prevention (CDC), approximately 1.7 million cases were reported in 2017, but the agency suspects up to 2.8 million people may actually be infected. Many infections with genital chlamydia go unreported because of vague or nonexistent symptoms, experts say.

Chlamydia is particularly common in younger people. According to the CDC, 1 in 20 sexually active young women between the ages of 14 and 24 are infected with the bacterium. Because chlamydia often has no symptoms, many men and women who have chlamydia may not know it, passing the infection to new partners or failing to get the necessary treatment. Chlamydia can be easily cured with antibiotics.

Ten to 15% of untreated chlamydial infections in women lead to symptomatic pelvic inflammatory disease, and some women with PID will develop infertility.

“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,” said immunologist Peter Andersen from the Statens Serum Institut in Denmark. Vertical transmission refers to the transmission of chlamydia from mother to infant during childbirth.

Chlamydia can cause complications in men, although they’re far less frequent. In rare cases, chlamydia in men is thought to cause prostatitis (inflammation of the prostate) or narrowing of the urethra. Although there are reports that it causes male infertility, studies do not support this.

What are the symptoms of chlamydia?

In most cases, chlamydia has no symptoms.

In women, chlamydia usually infects the cervix first, causing cervicitis, or inflammation of the cervix. That can cause feelings of pain, irritation, or a vaginal discharge. Chlamydia bacteria can also infect the urethra, leading to urethritis, which is often signified by pain while urinating.

In men, chlamydia bacteria can infect the urethra and lead to urethritis, a swelling in the urethra, which causes pain while urinating and discharge. The untreated bacterial infection can also cause epididymitis, a swelling in the tubes on the back of the testicles, causing pain.

In both women and men, chlamydia can infect the eyes, causing chlamydial conjunctivitis (a type of pinkeye). Symptoms include redness, irritation, and tearing. Chlamydia can also infect the rectum, either through anal sex or the spread of bacteria from the vagina. This might produce pain, discharge or bleeding, or no symptoms at all.

Chlamydia trachomatis is also responsible for lymphogranuloma venereum (LGV), a condition in which a different form (called a serotype) of the organism infects the lymphatic system, causing tender, swollen lymph nodes. It can also cause inflammation in the rectum accompanied by gastrointestinal symptoms.

Read more about the symptoms and complications of chlamydia here.

Researchers are particularly encouraged because the introduction of a vaccine against another common STI, human papillomavirus (HPV) has seen significant results.

Read more about HPV here.

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