Researchers have found that a cheaper, simplified method of administering the rabies vaccine gives as good an immune response as the standard, more expensive method.
This could benefit developing countries, where rabies vaccines are often unaffordable.
Following a bite or scratch from a possibly rabid animal, the standard treatment is a course of vaccine injections into the patient's muscle on five separate days.
Cheaper regimes are available and recommended by the WHO. These involve smaller doses of the vaccine injected at two or eight areas of the body on the first day, followed by later booster shots.
But these methods have not been widely adopted, largely due to practical difficulties. The vaccines, for example, only come in a standard dose with no preservative. This means at least two people need to be treated on the same day to avoid wastage.
In a new study, Mary Warrell, a clinical virologist from the Oxford Vaccine Group at the UK-based University of Oxford, and colleagues evaluated another method. Here patients are given a whole dose of vaccine on the first day, split over four sites around the body.
They compared their method with three other regimes in a trial of 254 healthy adults. The research, published in PLoS Neglected Tropical Diseases last week (22 April), found that all the cheaper methods elicited an antibody response just as effectively as the standard method.
Moreover, Warrell says the four-site method is safer than the other cheap methods, can be used with all available rabies vaccines and requires fewer clinic visits.
"You don't have to worry about wasting vaccine on the first crucial day. You give a large amount of vaccine initially — a strong stimulus for an immune response — and the patient has then got a week until they need the next dose," she told SciDev.Net.
Melinda Henry, WHO communications officer for immunisation, vaccines and biologicals, says the method has "good potential" and will be reviewed by the WHO in the near future.
Warrell says the need for wider adoption of a simpler protocol is becoming increasingly important as older vaccines are phased out by the WHO. This will increase the financial burden on developing countries with high levels of rabies, she says.
Rabies is a viral disease usually transmitted by a bite from an infected mammal. The infection is fatal to humans without preventative treatment. At least 55,000 people die from the disease annually in Africa and Asia.
PLoS Neglected Tropical Diseases doi 10.1371/journal.pntd.0000224 (2008)