An exciting, new dementia vaccine, the world's first, is being manufactured and tested through experiments  by Australian and US scientists. It may not only prevent but even reverse early stages of Alzheimer's, which is the most prevalent stage of dementia.

The vaccine may be tested on humans within the next two to three years, and may become available in five years. Scientists from Flinders University and America's Institute of Molecular Medicine and the University of California arrived at the breakthrough.

The disease affects 5.4 million American adults. Someone in the US develops the disease every 67 seconds The World Health Organisation (WHO) said that there are 7.7  million new cases of dementia every year. The total global societal cost of the illness and care is annually projected as US$600 billion.

The scientists' aim is to target proteins in the brain that are putting up blocks on neurons. The tau proteins and abnormal beta-amyloid leading to Alzheimer's and dementia can be removed. The first protein "to go wrong" is a beta, but working on removing the second protein tau can help to reverse the illness.

"Interestingly the second protein, which has been found more recently, which we are targeting ... it turns out if you target tau with the vaccine you can actually reverse the disease even once it has developed," said Petrovsky. Hence, the experts are targeting both proteins.

Flinders University medicine professor Nikolai Petrovsky said that they may be available ultimately as preventative vaccines.

"Essentially what we have designed is a vaccine that makes the immune system produce antibodies and those antibodies act like tow trucks so they come to your driveway, they latch on to the breakdown protein or car and they pull it out of the driveway," Petrovsky told 891 ABC

Petrovsky said that the vaccine was being "bankrolled by the world's biggest government," that is the US. Tests on humans will be conducted in the following two years.

The study was published in the journal Nature Scientific Reports