First Vaccine For Chlamydia Developed By McMaster Researchers

A vaccine designed to prevent the common sexually-transmitted infection (STI), chlamydia, has been developed by researchers at the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University. The widely protective vaccine is the first of its kind to treat the often-asymptomatic infection.

It’s estimated that 113 million people worldwide are affected by chlamydia each year, and are at risk of losing fertility as a result of the infection. The results of the McMaster study – published in the journal, Vaccine – found that a chlamydial antigen called BD584, could have protective effects against the most common species of the parasitic bacterium, known as Chlamydia trachomatis.

Chlamydia often goes untreated due to its asymptomatic tendencies, potentially leading to pelvic inflammatory disease, upper genital tract infections and infertility. According to Dr. David Bulir, a former PhD study in medical sciences at McMaster, and lead author on the study, a vaccine for chlamydia could be extremely beneficial for global health.

“Vaccine development efforts in the past three decades have been unproductive and there is no vaccine approved for use in humans,” said Bulir. “Vaccination would be the best way to way to prevent a chlamydia infection, and this study has identified important new antigens which could be used as part of a vaccine to prevent or eliminate the damaging reproductive consequences of untreated infections.”

Bulir and his colleagues found that BD584 was able to limit chlamydial shedding – a symptom of C. trachomatis infection – by 95 percent. The potential vaccine candidate also decreased the symptoms associated with blocked fallopian tubes, known as hydrosalpinx, by 87.5 percent.

“Not only is the vaccine effective, it also has the potential to be widely protective against all C. trachomatis strains, including those that cause trachoma,” said Steven Liang, a PhD student at McMaster and co-author on the study. Trachoma is an eye infection caused by the chlamydia bacteria and is the number one cause of preventable blindness around the world.

“The vaccine would be administered through the nose,” said Liang, in explaining how the immunization would be delivered. “This is easy and painless and does not require highly trained health professionals to administer, and that makes it an inexpensive solution for developing nations.”

Trachoma affects millions of people in mainly poorer regions around the world. The researchers say they plan to further develop different formulations of the vaccine, and test its effectiveness against other strains of chlamydia.