Chlamydia is a common sexually transmitted infection (STI) caused by the bacteria Chlamydia trachomatis. It is spread through unprotected vaginal, anal, or oral sex with someone who has chlamydia. Many people wonder if it is possible to develop immunity to chlamydia after being infected.
Can you become immune to chlamydia?
The short answer is no, it is not possible to become immune to chlamydia. Even after being treated and cured of a chlamydia infection, a person can become re-infected by exposure to chlamydia bacteria again. This is because the immune system does not build lasting immunity to the bacteria after exposure.
When a person is first infected with chlamydia, their immune system will start to produce antibodies to fight the infection. Antibodies are proteins made by the immune system that can recognize and neutralize specific pathogens like bacteria or viruses.
However, the antibodies produced in response to an initial chlamydia infection provide only short-term immunity. Studies show that immunity after clearing a chlamydia infection generally wanes after 6-24 months. After this time, a person can become susceptible to reinfection if exposed again.
Why you can become reinfected with chlamydia
There are several reasons why natural immunity does not develop against chlamydia:
- Chlamydia bacteria have evolved ways to evade detection by the immune system.
- Chlamydia infections target mucosal tissues like the cervix, urethra and rectum where immune responses are weaker.
- The antibodies produced in response to infection are not fully protective.
- Immunity is exposure site-specific – antibodies in the cervix don’t protect the urethra.
Additionally, research shows that recurring chlamydia infections are often caused by different strains of the bacteria. Exposure to a new chlamydia strain can bypass existing short-term immunity.
The risks of repeat chlamydia infections
It is estimated that about 20% of young sexually active women and about 10% of young men will become reinfected with chlamydia within 6 months of treatment. The CDC recommends rescreening for chlamydia 3-6 months after treatment.
Repeat chlamydia infections can increase the risk of serious reproductive health complications like pelvic inflammatory disease (PID) and infertility in women. Some studies have found over a quarter of repeat infections lead to PID compared to less than 10% of initial infections.
In men, complications like epididymitis and epididymo-orchitis are also more common with repeat chlamydia infections. Reinfections may also increase the risk of spreading chlamydia to partners.
Risk factors for repeat infection
Factors that increase the risk of becoming reinfected with chlamydia include:
- Having multiple or new sexual partners
- Inconsistent condom use
- Sex with partners who have not been treated
- Younger age – highest rates are in under 25s
How to reduce the risk of reinfection
To lower the risk of becoming reinfected with chlamydia after treatment, it is important to:
- Avoid unprotected sex for 7 days after finishing treatment and until partners have been treated.
- Use condoms correctly every time you have sex.
- Limit your number of sexual partners and avoid partners with unknown STI history.
- Talk to your partners about getting tested for STIs.
- Return for repeat STI screening 3-6 months after treatment.
Can a chlamydia vaccine provide immunity?
Currently there is no vaccine available to prevent chlamydia infection. However, researchers are working to develop a chlamydia vaccine.
Clinical trials have found potential chlamydia vaccine candidates can produce antibody responses against the bacteria initially. But like natural infection, this vaccine-induced immunity also declines after some months.
More research is still needed to create a vaccine that can provide long-term protective immunity against chlamydia. Some approaches being studied include nasal vaccines to boost mucosal immunity and using adjuvants to prolong immune responses.
Conclusion
In summary, it is not possible to become immune to chlamydia through natural infection. The immune system does not maintain long-lasting antibodies or immunity against chlamydia bacteria after exposure. Therefore, it is important to continue practicing safe sex and STI screening to reduce the significant risks associated with repeat chlamydia infections.
While developing a protective chlamydia vaccine remains challenging, researchers are optimistic improved understanding of the immune response to chlamydia will eventually lead to an effective vaccine that can provide long-term immunity against this prevalent STI.