'Once-only dose' rabies jab hope

Some 11,000 people are treated for rabies each year globally

Scientists say they have made a safe and effective rabies vaccine that requires only one dose and has the potential to eradicate the disease.

Rabies kills around 55,000 people every year and although there are effective treatments for the disease, prevention is seen as the most desirable option.

Attempts to eradicate rabies in dogs have been hampered by the expense and inefficiency of current vaccines.

Proceedings of the National Academy of Sciences reports on the latest trial.

Rabies is caused by a virus which attacks the nervous system.

We welcome any means of reducing the impact of rabies and believe this new vaccine will be a step forward to eradicate this deadly disease British Veterinary Association spokesman

Once symptoms appear it is almost always fatal, but people who contract rabies can be treated with a protracted course of antibodies and vaccinations to fight the virus after being bitten.

Eradication programmes are ongoing in parts of the world where the disease is prevalent in animals, mainly dogs, including Africa, Asia and parts of America.

But these efforts are blighted because effective and inexpensive vaccines are unavailable, say US experts from the Thomas Jefferson University in Philadelphia.

Single dose

What is needed, say Milosz Faber and his team, is a potent vaccine that will offer lifelong protection in just one simple dose.

To this end, they have developed a live-attenuated vaccine which contains a weakened form of the rabies virus.

In tests on mice, a single dose of the vaccine appeared to offer complete protection against a highly virulent strain of canine rabies.

It also cleared an established rabies infection from the brains of mice, suggesting it could be useful as a treatment in people who already have rabies.

The researchers said their vaccine could make global eradication of canine rabies feasible.

They told PNAS: "Inappropriate dog vaccination programmes, limited access to vaccination and post-exposure treatment of individuals who have been exposed to rabid dogs are major problems in developing countries.

"A live-attenuated rabies virus vaccine is likely to provide effective immunisation with a single dose, which has practical, cost and logistical advantages over conventional multidose vaccines with respect to the worldwide eradication of dog rabies."

A spokesman for the British Veterinary Association said: "Rabies is an enormous public health problem, particularly in developing countries, and potentially in developed countries.

"The UK has officially rabies free status since 1922 and the EU's Pet Travel Scheme has helped keep this status.

"However, rabies transmission by wild animals (e.g. bats and foxes) always pose a threat to the UK population.

"We welcome any means of reducing the impact of rabies and believe this new vaccine will be a step forward to eradicate this deadly disease."