First vaccine for chronic gum disease

A dental vaccine against severe gum disease which could eliminate or reduce the need for surgery for millions of people has been unveiled by Australian and US researchers.

Neil O’Brien-Simpson from the University of Melbourne and colleagues report their vaccine which targets the chronic bacterial condition periodontitis in NPJ Vaccines. 

Affecting a third of adults, moderate to severe periodontitis is a chronic inflammatory disease that destroys gum tissue and bone.

Rectifying the infection can mean surgery and antibiotics. But the disease often continues even after these treatments.

This is because it’s caused by a type of plaque that binds to the teeth and destroys the tooth’s supporting tissues, particularly the bony tooth sockets.

A bacterium called Porphyromonas gingivalis plays a key role. It buries itself deep in the gums around teeth and protects and feeds the rest of the microorganisms that comprise plaque, allowing it to flourish.

And once the bacterium reaches a certain level in the gums, it actually switched the body’s immune system to target local tissue, destroying the gums and teeth, instead of the microbes.

‘When you have a severe form, the tissue is highly ulcerated and the bacteria are entering the bloodstream,” explains Eric Reynolds, also at the University of Melbourne and senior author of the paper.

“They can be found in other organs, such as the pancreas and the brain.” And because of this, risk of cardiovascular disease, some cancers, arthritis and dementia also rise.

Enzymes produced by P. gingivalis called gingipains allow the bacteria to colonise teeth and break down tooth sockets. The vaccine developed by O’Brien-Simpson, Reynolds and colleagues targets these enzymes and halts their damaging rampage.

So while most vaccines aim to prevent a disease, this particular injection could be used to treat people already infected with the bacterium.

“Periodontitis is widespread and destructive. We hold high hopes for this vaccine to improve quality of life for millions of people,” Reynolds says.

The researchers spent 15 years studying the body’s immune response to the bacterium to see if they could switch it from destructive to protective. The resulting vaccine, Reynolds says, “neutralises the proteases, which are the key enzymes that cause disregulation of the immune response.

“But it also switches the immune response to a protective one where it produces antibodies that stop the destruction.”

The team hopes to commence human clinical trials as soon as 2018. For more, check out the video below.