Chlamydia

General Information

Chlamydia is a bacterial infection caused by Chlamydia trachomatis and is a common sexually-transmitted infection (STI).

Chlamydia infection can cause long-term complications in women including pelvic inflammatory disease (PID) and salpingitis, conditions that can lead to infertility and extra-uterine pregnancies.

Chlamydia is responsible for the majority of infection-related blindness worldwide.

Chlamydia is a preventable and curable STI.

Transmission

Sexually-transmitted infection. A pregnant woman with chlamydia can give the infection to her baby during childbirth.

Symptoms

Chlamydia infection is often asymptomatic. When there are symptoms, they may include unusual urethral and vaginal discharge.

Epidemiology

2020

In 2020 there were an estimated 128.5 million new chlamydia infections among adults (15–49 years old) globally.

Vaccines Pipeline

1
Vaccines in
the pipeline

IMMUNISATION TECHNOLOGY

mRNA (1)

DEVELOPMENT PHASES

Phase I (1)

TRIAL POPULATION

Adults (1)

Sources:
Mohseni M, Sung S, Takov V. Chlamydia. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537286/
Chlamydia. [Online]; 2024 [cited 2025 August]. Available from: https://www.who.int/news-room/fact-sheets/detail/chlamydia