Scientists develop Chlamydia vaccine

The first steps towards developing a vaccine against Chlamydia, an insidious sexual transmitted infection (STI) have been accomplished by researchers at McMaster University in Ontario.

Researchers at the Michael G. DeGroote Institute for Infectious Disease Research at McMaster have developed the first widely protective vaccine against chlamydia, a very common STI that is mostly asymptomatic but impacts 113 million people around the world each year and can result in infertility.

In their study, the researchers show that a novel chlamydial antigen known as BD584 is a potential vaccine candidate for the most common species of chlamydia known as Chlamydia trachomatis. BD584 was able to reduce chlamydial shedding – a symptom of Chlamydia trachomatis – by 95 per cent. The antigen also decreased hydrosalpinx, another Chlamydia trachomatis symptom which involves fallopian tubes being blocked with serous fluids, by 87.5 per cent.

Untreated Chlamydia can cause fallopian tubes to block

As most Chlamydia trachomatis infections are asymptomatic, chlamydia can often go untreated and lead to upper genital tract infections, pelvic inflammatory disease, and infertility. This is why the promise of a vaccine would be extremely beneficial, says David Bulir.

David Bulir says a vaccine ‘would be extremely beneficial’

“Vaccine development efforts in the past three decades have been unproductive and there is no vaccine approved for use in humans,” said Bulir, who has just completed his PhD in medical sciences at McMaster.

“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.”

“The results look very promising”, said James Mahony, Professor of Pathology and Molecular Medicine for McMaster’s Michael G. DeGroote School of Medicine and a researcher at St. Joseph Healthcare Hamilton’s Research Institute where the work was performed.

Co-author and McMaster PhD student, Steven Liang, explains, “not only is the vaccine effective, it also has the potential to be widely protective against all Chlamydia trachomatis strains, including those that cause trachoma.”

Trachoma is an eye infection caused by chlamydia and is the leading cause of preventable blindness affecting millions of people in many resource-poor regions of the world.

The next step? More testing for effectiveness against different strains of Chlamydia and in different formulations.